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Had some oil leak on the exhaust from the dipstick side that caused a fire!! Due to heat. It's 1991 L98 with 68k on the meter, automatic. And According to the mechanic oil is sipping from the dipstick due to pressure build up inside the engine... he is suspecting a pressure valve not working. Is this a possible cause?
Crankcase pressure with only 68K - hmmmmmmmmmm ...... this car have a blower on it ?
Do my crankcase pressure test - with engine at a hot idle remove oil fill cap. Great engine has no smoke but some smoke OK. What is not OK is "puffing". Place your palm close to opening - can you feel "puffing" ? If so probably a cracked piston. greg
Crankcase pressure with only 68K - hmmmmmmmmmm ...... this car have a blower on it ?
Do my crankcase pressure test - with engine at a hot idle remove oil fill cap. Great engine has no smoke but some smoke OK. What is not OK is "puffing". Place your palm close to opening - can you feel "puffing" ? If so probably a cracked piston. greg
the car is stock, I didn't check it myself yet but I'll do that. Any other signs for a cracked piston? Is it easy to fix if so?
the car is stock, I didn't check it myself yet but I'll do that. Any other signs for a cracked piston? Is it easy to fix if so?
Not really, it will require a rebuild of the engine.
After you do Blower Works "field test" and you are getting the "puffing" check your PCV value as a clogged valve will not let the internal pressure release and pumping out the dipstick is a logical escape route.
Any other oil leaks?
Last edited by billschroeder5842; 09-23-2017 at 09:51 AM.
Not really, it will require a rebuild of the engine.
After you do Blower Works "field test" and you are getting the "puffing" check your PCV value as a clogged valve will not let the internal pressure release and pumping out the dipstick is a logical escape route.
Any other oil leaks?
will check the valve also as it's is also suggested by the mechanic that could be not working.
No other major leaks but noticed some wet /stained oily areas in the front crank seal and the valve covers (I guess gasket replacement is required?)
will check the valve also as it's is also suggested by the mechanic that could be not working.
No other major leaks but noticed some wet /stained oily areas in the front crank seal and the valve covers (I guess gasket replacement is required?)
Lets check this one out first. If it is cracked, the new motor will be installed and there will be other priorities.
IDK if it is leaking all in the front. High point is the valve cover so lets start there. Clean it all off with brake cleaner and/or engine degreaser and lets start with dye and run the car for a bit. Observe every day.
Lets check this one out first. If it is cracked, the new motor will be installed and there will be other priorities.
IDK if it is leaking all in the front. High point is the valve cover so lets start there. Clean it all off with brake cleaner and/or engine degreaser and lets start with dye and run the car for a bit. Observe every day.
new motor..!! I hope it won't get to that. I mean I drove the car and so did the mechanic no whiered sounds, cracking, hitting...etc. it ran normal. I'm not an expert mechanic that's why I took it to one (I hope he is) and did the 134r conversion and oil and filter change all went ok, driving back home when I noticed smoke coming out from under the hood.. opened it and there was flames coming from bottom side just below the oil dipstick side! Took it back to the shop (recovery), was told that the fire was due to oil burning on the exhaust and that it was from the dipstick! AND that was due to pressure building up.
Maybe a sloppy oli change and didn't clean up an oops when filling the crankcase with oil and then concockting this explanation as a cya possibly? An oil fire after a recent lof sounds fishy to me.
new motor..!! I hope it won't get to that. I mean I drove the car and so did the mechanic no whiered sounds, cracking, hitting...etc. it ran normal. I'm not an expert mechanic that's why I took it to one (I hope he is) and did the 134r conversion and oil and filter change all went ok, driving back home when I noticed smoke coming out from under the hood.. opened it and there was flames coming from bottom side just below the oil dipstick side! Took it back to the shop (recovery), was told that the fire was due to oil burning on the exhaust and that it was from the dipstick! AND that was due to pressure building up.
If you get a cracked piston, it will be a new motor. That much oil means pressure in the crankcase from rings, or piston or even a cracked block, etc.
Maybe a sloppy oli change and didn't clean up an oops when filling the crankcase with oil and then concockting this explanation as a cya possibly? An oil fire after a recent lof sounds fishy to me.
Updates... so I did the test removed the PCV valve got it cleaned and cleared (was blocked) put all back and drove for a while... all seems ok and no oil dropping anywhere the mechanic will give it another spin and see.
Now for engine seals & gaskets; thinking of having them replaced as a service for the engine (I don't think any were changed before) as there are some signs/stains of oils mainly valve covers, crank.
any advise whether to buy them separately as required or there is a set that can be purchased for all the engine. Appreciate if anyone can point out which parts and supplier.
Updates... so I did the test removed the PCV valve got it cleaned and cleared (was blocked) put all back and drove for a while... all seems ok and no oil dropping anywhere the mechanic will give it another spin and see.
Now for engine seals & gaskets; thinking of having them replaced as a service for the engine (I don't think any were changed before) as there are some signs/stains of oils mainly valve covers, crank.
any advise whether to buy them separately as required or there is a set that can be purchased for all the engine. Appreciate if anyone can point out which parts and supplier.
TIA
So far so great ! lol
Hard to crack a piston w/o a blower so seems like everybody telling you just do normal maintenance is good advice.
BTW it has been my experience that all cars of this age should have the dipstick replaced - the seal ages and won't seal !!!
Updates... so I did the test removed the PCV valve got it cleaned and cleared (was blocked) put all back and drove for a while... all seems ok and no oil dropping anywhere the mechanic will give it another spin and see.
Now for engine seals & gaskets; thinking of having them replaced as a service for the engine (I don't think any were changed before) as there are some signs/stains of oils mainly valve covers, crank.
any advise whether to buy them separately as required or there is a set that can be purchased for all the engine. Appreciate if anyone can point out which parts and supplier.
TIA
Why do you clean the PCV? Isn't that just a replacement item?
Summit Racing or Jews will sell Fel Pro so that should be fine. Put dye after cleaning and let's see what happens
Thanks guys for the tips i really appreciate it...👍🏻
After test drive the mechanic said that no oil coming out anymore .. but he noticed little smoke instead, is that normal?
Should I do compression test also?
As for the PCV I could not find a replacement here I have to order it from states, but since I'm gonna place order I wanted to get as much parts as possible for shipping that's why I was asking about seals/gaskets or other spare parts for maintenance of the engine and probably for the transmission also just to keep them aside when needed.
I would really appreciate your feedback on that.
As I mentioned above smoke still coming out from the oil dipstick tube, I took a video of it while
idle, You can see the smoke coming out but Donno how to post the video here!!
And I noticed the oil pressure gage is on the high end!
change the oil filter. granted, there is an relief valve that's supposed to lift and bypass oil around a clogged oil filter, but you never know.
PCV test, remove the oil filter cap and lay a piece of lightwiehgt paper over the hole, a proper functioning PCV valve will put the crankcase into a vacuum and the paper will want to be sucked inward; a clogged PCV system or malfunctioning valve will allow normal piston blowby to pressurize the crankcase and tend to lift the paper up.
of course, even a properly operating PCV system can't keep up with massive amounts of blowby from bad / worn rings or a (unlikely) cracked piston.
Time for a compression test?
Last edited by mtwoolford; 09-28-2017 at 01:42 AM.
change the oil filter. granted, there is an relief valve that's supposed to lift and bypass oil around a clogged oil filter, but you never know.
PCV test, remove the oil filter cap and lay a piece of lightwiehgt paper over the hole, a proper functioning PCV valve will put the crankcase into a vacuum and the paper will want to be sucked inward; a clogged PCV system or malfunctioning valve will allow normal piston blowby to pressurize the crankcase and tend to lift the paper up.
of course, even a properly operating PCV system can't keep up with massive amounts of blowby from bad / worn rings or a (unlikely) cracked piston.
Time for a compression test?
oil and oil filter were changed last week, PCV cleaned (was clogged) and working, I'll try the paper thing.
the above can cause the smoke coming from dipstick tube? and high pressure on the gauge?
will the compression test indicates if rings needs to be replaced?
It is ok to drive it with this condition (high pressure n smoke)?
09-23-2017, 08:22 AM
Oil leak advise
the mechanic will give it another spin and see. 
so can you explain it pls[/QUOTE]
