Topic: Interesting problem
in Forum: C3 Engines
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
I've been fighting with the engine in my Vette for a while now. She was missing on the passenger side, so I replaced the distributor, which was in bad shape. No joy. Then the plugs (I had it done, didn't do it myself) Problem solved, but the guy said I needed new plug wires. I put that off until the problem reappeared. So, new plug wires. No joy. So I started pulling plugs. None of them were gapped right. 1, 2, 3, 4, 5, and 7 are starting to turn white. Lean mixture. Hmm. So then I pull 6. Wow. What a bunch of junk on that plug! "There's my problem", I think. Replaced that one and put it in the box, marking the cylinder. Then I pulled 8. Carbon city. Hmm. Lean on six cylinders, rich on two. So, what causes that? I still haven't replaced the intake manifold gaskets, which are leaking oil from two bolts, and I'm thinking that my be causing the problem. Any thoughts from you guys would be most welcome. By the way, the oil leaking from the intake manifold bolts is on the driver's side, the two bad plugs were from cylinders 6 and 8 on the passenger's side. This car does not smoke at all, but there was what looked like oil on the plug from 6. I'm baffled
.

SPONSOR AD:: (Our Sponsors help support C3VR)
Former Member
Send PM
Wayne, NJ - USA
Joined: 5/31/2002
Posts: 973
Vette(s): White 1975 L48 Stingray 129,000 Miles, daily driver.
I've been told by my regular mechanic(who supposedly has been ripping me off) that they could pull the motor, get it rebuilt by Jasper and put it back for approx $3000. That comes with 3 year 72,000 mile warranty.
Not saying you need a total rebuild, but you might spend quite a bit chasing down an elusive problem like that, and sure a total rebuild is overkill for most problems. I'm gonna bet you'd be happy with the way it runs when you get it back.
I haven't had my motor rebuilt, so I can't say from experience, but your problem sounds to be ... a real hair puller. Might be a fast solution and it would get the motor running right!
Scot
Not saying you need a total rebuild, but you might spend quite a bit chasing down an elusive problem like that, and sure a total rebuild is overkill for most problems. I'm gonna bet you'd be happy with the way it runs when you get it back.

I haven't had my motor rebuilt, so I can't say from experience, but your problem sounds to be ... a real hair puller. Might be a fast solution and it would get the motor running right!
Scot
I don't think it's quite time for a rebuild. I think I've got it narrowed down to two things. Either it is the intake manifold, or valve seals. The weird thing is that the car does not blow any smoke, but there is definately oil on the two plugs. Right now I figure I'll just do both repairs and see what happens. If she still has the same problem, I may do the rebuild.
Paragon75Ray said: I've been told by my regular mechanic(who supposedly has been ripping me off) that they could pull the motor, get it rebuilt by Jasper and put it back for approx $3000. That comes with 3 year 72,000 mile warranty. |
That sounds kinda high to me, unless you're adding some goodies.
14 dollars and 5 hours work! What a mess! It was definately the intake gaskets (I think, time will tell). Those gaskets were just gone. It took some time to clean out everything before we could put it back on. The timing is still off a couple of degrees, but I may just back off the throttle idle screw to get the RPMs back down because she's not pinging. I'll post back later with an update.
Ok, I've got her dialed in. Timing is advanced to 10 degrees and she runs a little stronger. No leaks around the manifold and I've got a silly grin on my face again
. This little exercise will hold me until I can afford the intake and carb next summer. She's running great, and no oil on the plugs!
As a bonus, now I know how to change out intake gaskets. Happiness is here again!


The solution for oil coming through the intake bolts is to remove them one at a time and put high temp sealant on the threads. I've only had trouble with the two that you mentioned, the inside two on the pass. side.
Charlie Carr
|IMG|http://thumbs.webshots.com/s/thumb4/6/58/92/88765892IdgKRN_th.jpg|/IMG|
Former Member
Send PM
Eastern part of, CT - USA
Joined: 1/29/2002
Posts: 319
Vette(s): White 73 convertible - 350/auto, A/C PS, PB, PW, leather, t/t, two tops
Also had a 69 t-top 20 years ago
Good job, contrail. SOmetimes a little detective work goes a long way. Joe
in Forum: C3 Engines
SPONSOR AD: (Our Sponsors help support C3VR)