Small oil leak around the lower corner of the engine cover? Maybe?

[billschroeder5842]

I've developed a small leak on the drivers side of the engine come from the area around the timing mark gauge. Of course is is a PITA to see and even more to put a hand on.

What I can see is that there seems to be leakage coming from the 10mm bolts on the lower left corner of the engine cover (water pump area?). This leakage seeps down and around the timing marker. I was able to put a 10mm deep on the three bolts (they seemed loose) and turn each 1/2 to 3/4 and get them snug. No way to put a torque wrench on them as there is no room.

Has anyone seen such a thing and/or how common? Of course a quick outing will tell if I got the problem, but is there anything else I should be checking?

Thanks!

[TX '90 ZR1]

Bill,
I had oil "seepage" in several areas when I got my '90.
It had about 33K on it. I found quite a few bolts/nuts not tight on the engine. Guessing nobody ever checked.
I went over the entire engine (rest of car also) and made sure everything was snugged up. Since doing this (about 3k miles) it is completely dry. I had it on the rack today and still bone dry.
Worth a try. :cheers:

[billschroeder5842]

Thanks TX'90,

I attacked the situation with a couple of rags and some 10mm's and put it on as many as I could get. Most needed a little snugging however, the three at the "bottom corner" seems a little looser- again 1/2 to 3/4 of a turn.

I'm taking her out today for my commute and will put an eyeball on it after work and see if the situation improved any.

Funny, I read the stickies and others and it seems pretty common that the bolts around the oil pan and the engine plate would become loose over time? Is that more of a result of "sloppy assembly" or aluminum expanding and contracting over time?

[lfalzarano]

I recall that the engine was assembled at a specific temperature. It is possible that running the engine at extreme heat and then cold could potentially loosen a few. Just a guess.


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[secondchance]

24 to 29 years don't help.

[indy91zr1]

Not to jack this thread but, i do have one question. Are there supposed to be two studs towards the bellhousing side of engine? I have two studs on both sides right before the 2 ten mils that are hidden up in inspection cover area. I was under the impression they are supposed to be bolts all around not studs.

[billschroeder5842]

I checked after my 40 mile drive yesterday and the leak area seemed much improved. I'm always hesitant to proclaim anything on our cars as "fixed" until after a few miles, however the snugging of the bolts did seem to make a difference.

I'll keep an eye on it.

[A26B]

Not to jack this thread but, i do have one question. Are there supposed to be two studs towards the bellhousing side of engine? I have two studs on both sides right before the 2 ten mils that are hidden up in inspection cover area. I was under the impression they are supposed to be bolts all around not studs.

I think you are referring to the 2 M8 studs at the top of the Front Cover. When the Front Cover is installed, those studs are secured with nuts in side the engine valley (under the plenum).

They are at the top-most location on the front cover, about 4" apart. Studs are secured to the Front Cover. Nuts have to be removed from the studs to remove the Front Cover.

[indy91zr1]

I think you are referring to the 2 M8 studs at the top of the Front Cover. When the Front Cover is installed, those studs are secured with nuts in side the engine valley (under the plenum).

They are at the top-most location on the front cover, about 4" apart. Studs are secured to the Front Cover. Nuts have to be removed from the studs to remove the Front Cover.

Hey Jerry thanks for the info,but these studs are on the back of the motor. I am gonna go ahead and assume that it has probably either had the gaskets replaced or motor has been out and fiddled with. There were some other questionable things I found that either previous owner had done. Let's put it this way, someone put a magnet in the gas tank to attract whatever rust there was in there. Now that is some ingenuity I will say but never in my life had I seen that.

[jss06c6]

I checked after my 40 mile drive yesterday and the leak area seemed much improved. I'm always hesitant to proclaim anything on our cars as "fixed" until after a few miles, however the snugging of the bolts did seem to make a difference.

I'll keep an eye on it.Good to know Bill. I'll add this to my check list... well done..

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[bhedberg]

Those studs, in addition to fastening the oil pan are to fasten the metal shields that go over the header cats on each side. A nut holds the shields onto those studs. This is for a 1990. Later years might differ.

[indy91zr1]

Those studs, in addition to fastening the oil pan are to fasten the metal shields that go over the header cats on each side. A nut holds the shields onto those studs. This is for a 1990. Later years might differ.

Ok thanks for the info. The car has longtubes on it and were on there when I bought it so that would explain why there were no heat shields on those studs.