C4 with leaky valve covers
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Joined: Mar 2015
Posts: 80
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From: Winchester Bay Oregon
John and corvette 40 My son went to a Napa store yesterday and the parts man who I have met and I believe is pretty knowledgable told my son Like you said John there is supposed to be only one pvc if you install two like my son's new to him c-4 as in the second photo someone installed a custom mesh covered hose from the throttle body to the second side with a pvc. He said that is not good as he has actually seen an oil pan partially collapse. The passenger side valve cover needs to have a vent in that hole otherwise vacuum to two sides has no way to get fresh air and will suck oil out of both valve covers therefore leaking around the pvc's like this car has. He said they did not have a filter for that valve cover but it needs to be changed soon as it could ruin a piston. I welcome comments on that? It makes sense to me. I would have to plug the vacuum from the one side of the throttle body and install a vent.in the valve cover. (apparently the leaky valve covers is better than plugging the intake line from the air cleaner at the throttle body)
One side should be PCV, and the other side should be CCV - Crank Case Ventilation, which goes to the throttle body. From the pictures above, it's plumbed right.
I have the same valve covers and the same problem. I tried a few sets of grommets till I found a set that fit the best, went to the hardware store and got brass bushing/caps that had a little cup at one side that the PCV valve and vent tube fit in, and that fit tighter in the grommet. They still leak. I have 1.6 rockers so there ain't many easy options.
I have the same valve covers and the same problem. I tried a few sets of grommets till I found a set that fit the best, went to the hardware store and got brass bushing/caps that had a little cup at one side that the PCV valve and vent tube fit in, and that fit tighter in the grommet. They still leak. I have 1.6 rockers so there ain't many easy options.
Last edited by wolfer; May 11, 2015 at 12:29 PM.
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Joined: Mar 2015
Posts: 80
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From: Winchester Bay Oregon
By the way John My son has never posted anywhere on any forum before this post. That is why it does not show where he is or any profile. I forgot to mention that to him so He thought he was getting flamed and never came back. My fault.
There is usually only a single PCV in the system. That does not mean that a previous owner didn't add one for some reason. There should be one coming from the valve cover and go to the throttle body your picture of the passenger's side of the engine. There should be and additional line from the other valve cover that ties into the intake manifold. If there is an additional PCV added, I don't see that as a major issue. The PCV is nothing more than a valve with a light weight spring that opens when there is pressure inside the valve cover. It would close if there was a backfire to prevent flames from entering the pan with all the vaporized oil which would result in damage to the engine. You are old school like myself and can remember when there were not PCV, but a pipe coming off the rear of the engine leading to the ground that released all the built up pressure in the pan. This changed to the PCV once the EPA got involved with our cars and said we could not have this just going into the air. So the PCV was invented so the oil vapor was sucked back into the engine usually at the base of the carb and burned. It has never been indicated if the PCV has been changed out for a new one. If the PCV is bad, it would allow pressure to build up and force small amounts of oil from any area that does not have a solid seal....such as the grommets in the covers. Possible solution is to remove the grommets, clean off the cover and the grommet with a solvent and re-install using a little silicone in the grommet groove. Silicone has to sit 24 hours to set. The other possibility is that you have blow by from a cylinder or two from a tired engine. You could do a compression check, the cylinders should be within 10 pounds of each other. If you do the compression check and find that a cylinder or two are low, then the engine is acting like a air pump and adding pressure to the lower part of the engine (oil pan). The pressure builds and has to find an exit to release this pressure. The air in the pan is filled with oil mist and will be carried by the air as it releases the pressure the any exit it may find. That is were your oil running down the covers could be coming from. If you PVC is not functioning properly, it only multiplies the problem.
It is a good thing if you can pass on your knowledge about cars and engines to your son. Not enough of this is done today.
Many of us have been on this Forum for years and try to contribute our experiences and knowledge to those that ask for help. We find that the posts are asking for help with a problem. For every 1000 posts here there is one that says...hey guys there is nothing wrong with my car and I just wanted to let you know. Some of the members here are more adapt at making a good valid diagnosis and providing a solution than others. Unfortunately it is up to the original poster to sort thru the answers and apply what they feel is the solution. Often it is not a easy thing to provide a solution given the limited amount of information that we receive about the problem.
You are new here, so you should realize that we have people that post just to stir up problems and waste the time of members here that are here to help. They make a post and then disappear in the wind. Your son makes a similar post to your initial post (no city or state tied to the post by your son) using the same pictures. Our first impression is TROLL for the second post. Wolfer, your post was given solutions and you interacted with those that posted possible solutions. Your son makes a couple of additional posts of pictures, but never a response to the link to your post and solutions given there. Nor is there a response that he has tried any of the suggestions given.
It is a good thing if you can pass on your knowledge about cars and engines to your son. Not enough of this is done today.
Many of us have been on this Forum for years and try to contribute our experiences and knowledge to those that ask for help. We find that the posts are asking for help with a problem. For every 1000 posts here there is one that says...hey guys there is nothing wrong with my car and I just wanted to let you know. Some of the members here are more adapt at making a good valid diagnosis and providing a solution than others. Unfortunately it is up to the original poster to sort thru the answers and apply what they feel is the solution. Often it is not a easy thing to provide a solution given the limited amount of information that we receive about the problem.
You are new here, so you should realize that we have people that post just to stir up problems and waste the time of members here that are here to help. They make a post and then disappear in the wind. Your son makes a similar post to your initial post (no city or state tied to the post by your son) using the same pictures. Our first impression is TROLL for the second post. Wolfer, your post was given solutions and you interacted with those that posted possible solutions. Your son makes a couple of additional posts of pictures, but never a response to the link to your post and solutions given there. Nor is there a response that he has tried any of the suggestions given.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Wolfer, that makes sense from a practical common sense angle. The only part that doesn't make sense is that if you create a vacuum that would collapse the oil pan you would not be forcing oil out the grommets. Common sense tells me that the pan is still be pressurized and the pressure is not being released the way the system was designed.
You should not plug the line, just remove the PCV valve and replace it with a plastic 90. Napa or another auto parts store should have something that would fit snugly into the grommet and plug into the hose. The PCV valve should go into the driver's side valve cover. Pull the PCV valve in the passenger's valve cover and replace it with the unrestricted 90. This should still be plugged into the hose that goes to the fitting on the throttle body as shown in your picture.
I would still suggest using silicone on the grommet groves.
You should not plug the line, just remove the PCV valve and replace it with a plastic 90. Napa or another auto parts store should have something that would fit snugly into the grommet and plug into the hose. The PCV valve should go into the driver's side valve cover. Pull the PCV valve in the passenger's valve cover and replace it with the unrestricted 90. This should still be plugged into the hose that goes to the fitting on the throttle body as shown in your picture.
I would still suggest using silicone on the grommet groves.
Last edited by John A. Marker; May 3, 2015 at 07:45 PM.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Looking at the posted picture of your valve covers, it looks like they are stamped metal. This would lead me to speculate that the metal is much thinner than the standard OEM valve cover which would be thicker. So it this is actually the case, the grommet groove is wider than the thickness of the cover meta. This would give you a sloppy fit....and lead to an oil leak. This might also be the same case with the plug you remove in the cover to fill the engine with oil.
Silicone on the grommets and see if you can add or make a gasket to tighten the oil filler plug in the cover.
Tell you son to come back and share his experience on the repair. Now that we know the back story we will not pick on him. If he wants to get picked on, then he should post anything in the OFF TOPIC section....they can be brutal at times.
Silicone on the grommets and see if you can add or make a gasket to tighten the oil filler plug in the cover.
Tell you son to come back and share his experience on the repair. Now that we know the back story we will not pick on him. If he wants to get picked on, then he should post anything in the OFF TOPIC section....they can be brutal at times.
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Joined: Mar 2015
Posts: 80
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From: Winchester Bay Oregon
John major disaster my son called me a couple hours ago and I had sent him to the parts house to get a vent filter to replace the second pvc and He disconnected the hose and plugged the vacuum line While he was sitting at the parts store. He called me because the starter quit. He lives 20 miles north of me so I got into the car and went to rescue him. When I got there I asked him what the starter was doing and he said it made a thud so I figured it maybe got stuck in the flywheel and it was not clicking like a solenoid so I told him to go ahead and try to start it so I could hear it fortunately it started right up. It had a little miss and white smoke was coming out both exhaust pipes. I followed him home and it was blowing white smoke all the way home and when he got there it was 217 degrees so I told him to turn it off. He said it sometimes when idleing will go to about 124 degrees then the fan kicks on and cools back down but I was not sure about the smoke I let it cool a little and checked the overflow bottle and it was empty so I lossened the radiator cap and it was low on fluid. we added some water after it cooled and fired it up again it blew tons of white smoke so I thought it could be a head gasket so I checked the oil the water and oil showed no sign of mixing. Is it more than likely a head gasket? I tried to leave the radiator cap off to see if there were any air bubbles in it but it just blew water out when we started it.
Looking at the posted picture of your valve covers, it looks like they are stamped metal. This would lead me to speculate that the metal is much thinner than the standard OEM valve cover which would be thicker. So it this is actually the case, the grommet groove is wider than the thickness of the cover meta. This would give you a sloppy fit....and lead to an oil leak. This might also be the same case with the plug you remove in the cover to fill the engine with oil.
Silicone on the grommets and see if you can add or make a gasket to tighten the oil filler plug in the cover.
Tell you son to come back and share his experience on the repair. Now that we know the back story we will not pick on him. If he wants to get picked on, then he should post anything in the OFF TOPIC section....they can be brutal at times.
Silicone on the grommets and see if you can add or make a gasket to tighten the oil filler plug in the cover.
Tell you son to come back and share his experience on the repair. Now that we know the back story we will not pick on him. If he wants to get picked on, then he should post anything in the OFF TOPIC section....they can be brutal at times.
Melting Slicks
Joined: Jun 1999
Posts: 2,931
Likes: 127
From: Ashland Alabama
Try putting the hose back like it was. See if the smoke goes away.
Sounds like a bandaid fix the previous owner did and when he tried putting it back right the problem showed up.
As to what the real problem is that's hard to say over the net and all. Could be valve seals for one thing. Are you sure its water out the tail pipes and not oil smoke? Some synthetics burn out as white looking smoke.
Sounds like a bandaid fix the previous owner did and when he tried putting it back right the problem showed up.
As to what the real problem is that's hard to say over the net and all. Could be valve seals for one thing. Are you sure its water out the tail pipes and not oil smoke? Some synthetics burn out as white looking smoke.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Yes, sounds like head gasket. Check out his thread....
https://www.corvetteforum.com/forums...ad-gasket.html
Sounds like you can rent a tool to check for exhaust gasses in the coolant. My past experience has shown that the head gaskets commonly fail on cylinders #7 and #8. The coolant passage for these cylinders at the rear of the block are VERY CLOSE to the cylinder walls. The other issue you have is that the block is cast iron and the heads are aluminum. Two different metals that expand and contract at different rates. This then results in the gasket being the mating surface between the two metals that has to flex. Eventually something has to give.....the gasket.
217 degrees is not hot for these cars.
Look at anything that he recently did to the car. You indicated that he pulled the vacuum line and plugged it. Anything else? It doesn't seem like pulling and plugging the line would suck in coolant into the engine, but anything is possible.
with crowz, try and hook the vacuum line back up like it was and see if there is any difference. It may take a while to test if you have sucked coolant into the exhaust system. It will take a while to burn it off.
https://www.corvetteforum.com/forums...ad-gasket.html
Sounds like you can rent a tool to check for exhaust gasses in the coolant. My past experience has shown that the head gaskets commonly fail on cylinders #7 and #8. The coolant passage for these cylinders at the rear of the block are VERY CLOSE to the cylinder walls. The other issue you have is that the block is cast iron and the heads are aluminum. Two different metals that expand and contract at different rates. This then results in the gasket being the mating surface between the two metals that has to flex. Eventually something has to give.....the gasket.
217 degrees is not hot for these cars.
Look at anything that he recently did to the car. You indicated that he pulled the vacuum line and plugged it. Anything else? It doesn't seem like pulling and plugging the line would suck in coolant into the engine, but anything is possible.
with crowz, try and hook the vacuum line back up like it was and see if there is any difference. It may take a while to test if you have sucked coolant into the exhaust system. It will take a while to burn it off.
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Joined: Mar 2015
Posts: 80
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From: Winchester Bay Oregon
Everywhere I read it needs CCV crankcase ventilation not two pcv valves. I have been searching the internet last night and have some hopes. Yes it is not smoke it is steam. It goes away quickly it is wet when I held my hand at the end of the tailpipe nothing inside the tailpipe when I run my finger in all 4 openings. they were dry and just a black finger from carbon. I followed him home and it put steam out both sides. Not sure if the exhaust has a crossover pipe underneath but smoke is equal on both sides. I switched it back and we drove it a couple miles down the road and back and there was a little steam while going down the road but when we got back it was 197 degrees but started getting hotter while idleing he said that was normal for the car. He told me it was not uncommon for it to go up to 224 degrees then the fan would come on and cool it back down. I gave him one of my cars to drive to work and I will be gone today but I will first take out the spark plugs tomorrow and check them out while doing a compression test. Since it is both sides steaming equal I read where it may be a vacuum modulator on the tranny due to what we did with vacuum. Or it may possibly be an intake gasket leaking. I have never had a fuel injected intake off before but know how to change head gaskets. Just worried about getting the intake back together. Others I read with problems drove theirs to see if it got hot,or the oil mixed or the atf level was dropping. So far the oil is clear. Everywhere I read every schematic I could find for 350s said one pcv valve and one ccv. Is there a ccv valve that is similar to a pvc? or is a filtered vent what they mean? Sorry for the long post. I will be back in a couple days and report in.
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Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Pull plug #7 and #8 and look at the ceramic. Does one plug look extremely clean like it is new? If you have a leaking head gasket and it is spraying coolant into the cylinder it will wash the ceramic clean.
The intake is not bad. Just remember that there are different size bolts holding the runners in place and (from memory) two bolts under the plenum that hold the runners to the intake. Leave the fuel rails with the injectors on the intake. No need to take them off....just extra work that you don't need to do. Disconnect the fuel lines from the front of the rails. You will need a couple of rubber caps to place over the fuel lines to prevent them from leaking. The intake is just like the old intakes for a carb with the exception that there are holes in the runners for the injectors.
Note that the tranny is not connected in any way to any coolant source.
If you do replace the intake or head gaskets, save yourself some grief and label each bolt, nut, wire, hose, brackets and anything else you remove. Take pictures or make drawings to help you know exactly where things came from. Don't rely on your memory...just too may things to take off.
The intake is not bad. Just remember that there are different size bolts holding the runners in place and (from memory) two bolts under the plenum that hold the runners to the intake. Leave the fuel rails with the injectors on the intake. No need to take them off....just extra work that you don't need to do. Disconnect the fuel lines from the front of the rails. You will need a couple of rubber caps to place over the fuel lines to prevent them from leaking. The intake is just like the old intakes for a carb with the exception that there are holes in the runners for the injectors.
Note that the tranny is not connected in any way to any coolant source.
If you do replace the intake or head gaskets, save yourself some grief and label each bolt, nut, wire, hose, brackets and anything else you remove. Take pictures or make drawings to help you know exactly where things came from. Don't rely on your memory...just too may things to take off.
Advanced
Joined: Mar 2015
Posts: 80
Likes: 0
From: Winchester Bay Oregon
I have been doing some research
One side should be PCV, and the other side should be CCV - Crank Case Ventilation, which goes to the throttle body. From the pictures above, it's plumbed right.
I have the same valve covers and the same problem. I tried a few sets of grommets till I found a set that fit the best, went to the hardware store and got brass bushing/caps that had a little cup at one side that the PCV valve and vent tube fit in, and that fit tighter in the grommet. They still leak. I have 1.6 rockers so there ain't many easy options.
I have the same valve covers and the same problem. I tried a few sets of grommets till I found a set that fit the best, went to the hardware store and got brass bushing/caps that had a little cup at one side that the PCV valve and vent tube fit in, and that fit tighter in the grommet. They still leak. I have 1.6 rockers so there ain't many easy options.
I think you are spot on I think the 89 was a one year pcv ccv system. Here is a diagram I dug up from previous posts on this forum. From what I gather the pass side has a CCV valve which is no longer available from GM I am not sure if what this car has is a ccv or a pvc someone put in that valve cover or if they are different. If I can figure this out I may take a stab at tearing this engine down but not til this issue is resolved. Any help appreciated as we cannot afford to put it in a shop at this time my son is saving his money to put it back on the road again.
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
Wolfer, I too am similar to your experience. Got out of the army in 74. Over the road truck driver,Worked on cars since I was a kid and have rebuilt a few engines. My vette was totally intimidating to me , all that electronic gizmos, wires, and such. I pulled off my injection system. Wolfer, its all the same (almost) as the old SBC. As noted above, write down where the runner bolts (length) are and the wires. I didn't and had to go the long way around to get it all back together (pull again a few times). Good luck and I wish I could spend time with my son doing something like that.
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Joined: Mar 2015
Posts: 80
Likes: 0
From: Winchester Bay Oregon
Wolfer, I too am similar to your experience. Got out of the army in 74. Over the road truck driver,Worked on cars since I was a kid and have rebuilt a few engines. My vette was totally intimidating to me , all that electronic gizmos, wires, and such. I pulled off my injection system. Wolfer, its all the same (almost) as the old SBC. As noted above, write down where the runner bolts (length) are and the wires. I didn't and had to go the long way around to get it all back together (pull again a few times). Good luck and I wish I could spend time with my son doing something like that.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
If you have done engine rebuilds in the past and replaced head gaskets, the basics have not changed. You just have a few more gaskets and parts to take off. As I said before, just label every wire, hose, bolt, nut and parts to their exact location. Take pictures close ups and make drawings to confirm locations. You have more sensors that your 70's and 80's cars. Leave the fuel rails on the intake manifold. You will have to cap off the fuel lines on the front where they connect to the rails to prevent fuel leaking. Other than that....everything is the same as what you have done in the past. There is more aluminum on these cars, so if a bolt threads into aluminum just be sure to coat the threads with anti-seize.
Don't let fuel injection scare you off.
Don't let fuel injection scare you off.
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Joined: Mar 2015
Posts: 80
Likes: 0
From: Winchester Bay Oregon
I still need to know if someone can tell me how to differentiate between the pvc and ccv valves. I do not want to do heads twice. When Judd Plugged the intake from the air cleaner and added a filtered vent in the valve cover we lost the head gasket. I believe this is only plumbed this way in the 89 year model.
If you have done engine rebuilds in the past and replaced head gaskets, the basics have not changed. You just have a few more gaskets and parts to take off. As I said before, just label every wire, hose, bolt, nut and parts to their exact location. Take pictures close ups and make drawings to confirm locations. You have more sensors that your 70's and 80's cars. Leave the fuel rails on the intake manifold. You will have to cap off the fuel lines on the front where they connect to the rails to prevent fuel leaking. Other than that....everything is the same as what you have done in the past. There is more aluminum on these cars, so if a bolt threads into aluminum just be sure to coat the threads with anti-seize.
Don't let fuel injection scare you off.
Don't let fuel injection scare you off.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
The PCV valve should be metal on the end that plugs into the cover. If you look at it, there should be a hole in the base that is covered by another metal piece in the inside. If you shake it, it should rattle.
You CCV should probably be 100 plastic and wide open...no restrictions. When checking various auto parts web sites, there is no listing for a CCV. You should be able to find a plastic 90 degree that will fit into the grommet and connect to the hose.
You CCV should probably be 100 plastic and wide open...no restrictions. When checking various auto parts web sites, there is no listing for a CCV. You should be able to find a plastic 90 degree that will fit into the grommet and connect to the hose.
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Joined: Mar 2015
Posts: 80
Likes: 0
From: Winchester Bay Oregon
From what is previous posts here it has to be balanced with intake and outflow. open would put it out of balance. I also read which does not suprise me that it is not stocked as oem any more. It appears I have two pvc valves as they look the same and rattle. I did not lose the head gasket until he closed the port on the throttle body just behind the air cleaner and put a vent in the valve cover. Our first problem was leaking and smelling from both the pvc's and the oil fill which is just a rubber plug.
John I may have really screwed the engine up when I had him block that plug as by the time I got there it was steaming out both exhaust pipes. white steam that evaporated quickly. It did not overheat but I had him shut it down. It was low on water by then and he has been watching the water level closely for a while. We pulled the #7 plug and it was damp and clean. Not dry like it should be. I hooked up a compression gage and it registered 122# when I pushed the button to release the pressure it blew milky water all over the place. I then tried to blow the water out of the cylinder with no plug in the hole and it bound up and no water came out. I figured it took a rod or piston. I took all of the plugs out then and it was the only one that was wet but some were black tips and some were white to brown tips.
The PCV valve should be metal on the end that plugs into the cover. If you look at it, there should be a hole in the base that is covered by another metal piece in the inside. If you shake it, it should rattle.
You CCV should probably be 100 plastic and wide open...no restrictions. When checking various auto parts web sites, there is no listing for a CCV. You should be able to find a plastic 90 degree that will fit into the grommet and connect to the hose.
You CCV should probably be 100 plastic and wide open...no restrictions. When checking various auto parts web sites, there is no listing for a CCV. You should be able to find a plastic 90 degree that will fit into the grommet and connect to the hose.
Last edited by wolfer; May 11, 2015 at 12:43 PM.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
If you got milky water from that plug.....no question....blown gasket.
There is no true "balance" from one valve cover to the next. The pan naturally pressurizes with the small amount of blow by the rings and the pistons moving up and down. Just use the one PVC and put a open 90 on the other side. The PCV valve is to prevent a backfire (flames) from reaching the valve covers.
Looks like you will be replacing a head gasket. set.
There is no true "balance" from one valve cover to the next. The pan naturally pressurizes with the small amount of blow by the rings and the pistons moving up and down. Just use the one PVC and put a open 90 on the other side. The PCV valve is to prevent a backfire (flames) from reaching the valve covers.
Looks like you will be replacing a head gasket. set.