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Yep. I opted to get the full set of top-end gaskets from Jerry's. They just arrived, so I'll be pulling the fuel rails and injectors tomorrow to replace all the seals before putting everything back together. With a little luck, and another set of hands... I could have the car back on the road tomorrow afternoon.
I have the long-tube headers in my sites... but that will be for another day. My main goal is to figure out if the oil leak has been fixed, and if not... where is it coming from? I'll do a little searching for the exhaust manifold studs and associated oil leak. If I need to fix that... I'll do the headers at the same time. I'm gonna ignore all the other issues mentioned here until I can get it driving, enjoy it a little, and figure out where the rest of the immediate gremlins are hanging out.
Great article. From the looks of things, it appears my oil pan gasket is kaput. I could have multiple problems, but that appears to be the biggest source right now.
Great article. From the looks of things, it appears my oil pan gasket is kaput. I could have multiple problems, but that appears to be the biggest source right now.
-Gonzo
Before you go to all that trouble, simply re-tighten all the oil pan bolts. You be amazed how loose they are. More often that not that by itself stops the leaks at the pan. You’ll have to remove the “K” supports to get to the front bolts that do most of the leaking. Just unbolt the “K” members and remove. They do not support the engine even though the engine mount lower stud goes through them.
H
Another fun day with the new Vette. I believe the Underside is just about cleaned up from road grime. I'll probably do a finer pass before getting it back on the road.
I will tighten the oil pan bolts before remove the pan... but with all the muck around there, I'm not sure tightening the bolts is gonna do it. A lot of oil has come out of there. There's a ton of gunk all around there. My guess is the oil pan gasket I ordered today is gonna find its way on to my LT5 in the next week or so.
Today started with pulling the fuel rails and the injectors. Things went mostly according to plan. I undid the clips for each injector, and pried on the rails. The rails came up with about half the injectors. The other injectors stayed in the heads where I pulled them up one at a time.
It became quickly apparent that the secondary injectors had not been used since at least George W was in the White House. The O-rings were toast on both sets, but the secondary injectors were especially bad The amount of carbon build-up was unreal. When I looked closer at the plenum (upper and lower), the secondary sides looked like they were coated in charcoal. I thought this might be the case being that nearly all ZR1s I've ever seen have had the valet-key permanently located in the dash... all but this one. In fact, the valet keys were stored in a different location than the car keys when I bought the car. Unreal.
With a little carb-cleaner, the injectors cleaned up quite well. Installed the upper and lower O-rings... and we were ready to go. Of course, I also found a little more rat urine that I missed from before. NOW... things are clean and ready to go back in the car.
Then came what I thought would be a nice side project... Remove the coolant outlets. I planned to drill and plug the upper portion of the plenum, but then thought about it and figured that plugging the head side would be far better being that then no coolant would ever touch the plenum gaskets. I wanted to get the coolant outlets off so I could stuff a shop-vac in there while I drilled and tap'd the plug holes. So... I immediately broke / stripped 5 of the 8 bolts. Oh joy. For what it's worth, I wasn't the one that put the wrench marks in the outlet pipe below. It's pretty clear someone struggled with this in the past as much as I had to. This was a GIANT PITA. I drilled out the heads, but these things didn't even budge. I hit it with a rubber mallet a couple times to no affect before I did some searching to figure out what other people did... lots of heat... and more heat.
I tried a propane torch. Still no help. I had to go buy a MAP torch to get things hotter. Eventually, I could start prying the outlets away from the heads. The funny part was that when I finally got the outlet boxes pulled over the studs, the head-less bolts unscrewed with my fingers. The issue was that the bolts had corroded so badly, they'd fused with the box. Seems like a bad design... and something that will happen every couple years if you don't change these bolts out. I think I'll add this to my list of things to do every couple years with this car.
And then I ran out of time. Back-to-school night. Getting this all back together on Monday. The good news is - all the cleaning and fixing is compete. Now I just need to put it all back together... do more cleaning... and finally drive it at more than idle speeds... AND WITH FUNCTIONING SECONDARIES!!!
-Gonzo
Last edited by Gonzo_65_L76; 09-08-2018 at 11:27 AM.
From the looks of those O rings, you would be wise to check the resistance of each injector before you reinstall them. The winding insulation in OEM injectors prior to 1993 are known to deteriorate from ethanol exposure and cause the injectors to fail. I bet the deterioration of those o rings is evidence of that as well.
Be sure your new O rings are impervious to this. Jerry's Vitol O rings are a good choice.
At the very least, re-torq those injector housing bolts while your there. As previously stated replacing the lower gaskets would be preferable. I have some spare coolant tube bolts if you want them. Free.
H
While I'm waiting on parts... I'm thinking not might be a good time to send in the injector housing, plenum and TB for a top-end porting at Haibeck. Part of me sees a little risk in this being that I haven't really driven this car since buying it. I've really only just idled it ~1/4 mile to my garage. It's possible there are bigger engine issues yet to be uncovered. That said, I doubt there's anything that would render the LT5 unsalvageable being that it did start right up, and it ran without any horrible banging noises.
Today I decided to attack the oil leaks while I wait for my new injectors. Yes, I first tried to re-torque the bolts. Yes, some of the side bolts were less than 23 ft-lbs, but the fronts were actually over-tight... which was where the oil was leaking the worst. With that, I didn't see any alternative to pulling the pan.
Step one: drain oil.
Ugh. The drain plug was so over-torqued... my guess is I used between 60 and 75 ft-lbs to get the oil plug bolt out. The bolt was already slightly rounded from over-torqueing, so it didn't take much for me to round it completely. Dig out the extractor-sockets and get it out. Good thing I ordered a new plug last week.
As expected, once I got the pan off, the gasket at the front of the pan was a mess. There was actually grime under the gasket that was preventing a sufficient seal. There was a nice flow of oil moving under the gasket. You can actually see it in the pictures below if you look closely. My guess is that the front of the pan got loose enough to allow in dirt. Some genius then decided to over-torque the bolts to try and fix the problem, but it was too late.
Tomorrow I will take the windage tray out of the pan and clean everything up (thanks to the Jerry's pan installation guide). Hopefully I will have time tomorrow to finish this work, and get the pan and new gasket (with some Permatex Super "300" Form A Gasket) back on to the engine. I'm hoping to have the new injectors from Jerry's tomorrow afternoon / Thursday. I'm still hopeful I can finally drive this thing over the weekend.
The good news is each layer deeper I go, the cleaner things are getting.
Onward.
-Gonzo
Last edited by Gonzo_65_L76; 09-12-2018 at 10:25 AM.
Before you put the top back together, measure the primary and secondary resistance of each coil to be sure they are in spec. It will save having to remove the plenum again if you start to question your spark intensity. The LT5 uses a dual spark design which fires two cylinders simultaneously but only the cylinder in compression will get a high intensity spark while the other gets a weak spark. This makes it difficult or impossible to find a weak coil by pulling a plug wire and testing the typical way.
I made a decision to enjoy unemployment until the end of this calendar year. This is the perfect time to rescue a ZR1 from a barn guarded by a hoard of rats.
This forum is the only reason I'm making progress at the rate I am.
I made a decision to enjoy unemployment until the end of this calendar year. This is the perfect time to rescue a ZR1 from a barn guarded by a hoard of rats.
This forum is the only reason I'm making progress at the rate I am.
-Gonzo
Can't say I'm enjoying unemployment but for sure it's a great opportunity to tear into a sick Z and you are spot on making this one right again. I wouldn't hesitate a minute getting the porting work done and consider refinishing the cam covers and plenum if budget allows.
I've been running around with a relatively groty engine for too long. In my case a failed head gasket made it necessary. The early cars really wake up from taking out the injector boss, and of course head porting is the next around the corner.
I'd take a hard look at the accel injectors as they seem to work well, are cheaper, and tune nicely (good data, very linear).
Keep us posted, and make sure you check that the pan wasn't warped by prior ham fisted torque wrenches. Amazing that the little 7mm guys didn't pull threads!
Check the side bolts on the headers as some of them are prone to weeping oil too as well as the oil pressure switches.
the bottom end will likely NOT give issue, and it's why most love the lt5 so much.
Powdercoating like above will make your motor stand out....However, from what I understand regular high temp spray paint will work as well....I think Jerrys actually supplies a spray that gets close to the factory finish.....The finish on these motors and cam covers just fade over time...
Wonder among wonders... the coils APPEAR to resist within range on both the primaries and the secondaries!!! Sorry Jerry... No coil order for me.
For reference, The primaries should resist between .35 and 1.45 ohms. The secondaries should resist between 5k and 6.5k ohms.
The trick will be if they work with heat and high-voltage, but for now... I'm putting the pack back together and re-installing it ... after I clean up off the rat urine I found on the plate under each of the coils.
I opted to not send the top-end bits to Haibeck right now. They currently have a one month turn-around on all porting work. I'm hoping to finally drive this beast in another 2-4 days (depending on when new injectors arrive). I'll plan to send MarcH a package after I drive this for a while and work out the rest of the gremlins. Then I'll send him everything, including the heads.
Gonzo, I was exploring the forum this afternoon and found this thread. Congrats on your new car. I enjoyed your thread on the C2 forum with the replacement engine on your 65. Good luck with your new ZR1.
09-06-2018, 08:28 PM
