The vehicle -- '89 Raider 3.0L, 225,000 miles on the odometer, bone stock, heads have never been done as far as I know. In the last 3 years the intake manifold gaskets, valve stem seals, HLAs, timing belt and water pump have all been replaced.

The Raider is starting to have an issue with smoke from the exhaust. At first, I noticed it only on cold start, but now I'm noticing it after warm start up as well.

I thought it might be a slightly breached head gasket because I am slowly losing coolant (as in the overflow tank goes down in about a 1 to 1.5 weeks), but no sign of coolant in the oil, or vice versa. I'm detecting some signs of the radiator cap leaking so this might explain the coolant loss.

Operating under the assumption that it might be a head gasket, I ran a compression test yesterday (plugs out, engine warm, cranked for 7 times each cylinder, but I did not hold the throttle open) with the following results:

1 -- ~180 psi
2 -- ~180 psi
3 -- ~175 psi
4 -- ~180 psi
5 -- ~180 psi
6 -- ~180 psi

The only value I can find for compression is the limit value of 119 psi. Are the above decent values, or are they on the high end (which apparently would mean the combustion chambers are carbon-caked and the heads need to be cleaned)? I didn't re-take compression readings "wet", because these seemed pretty decent to me.

What would y'all recommend I look at next? The plugs are relatively new and looked OK to my admittedly un-trained eye. I would have thought there would be a wider variation on the compression readings if there was an issue with a dropped valve guide or something. Is it possible the valve stem seals have failed in this time frame/mileage (2-3 years, maybe 20K miles, I don't have my records handy right now)?

Really not wanting to drive it much with the smoke screen it is laying down... <img src="/forums/images/graemlins/baby.gif" alt="" />

Any insights and suggestions would be appreciated!

Eric W.

What does the smoke smell like? Like gas or very hot oil, or sweetish? Does it smoke heavily after you idle for several minutes, like at a red light after being warmed up?

I'd try to retorque the head bolts and do a radiator pressure test (you can rent the tester from autozone or advanced or several other parts houses).

Possibilities: Leaking injector, head gasket, valve stem seals. I'd tend to rule out rings due to good compression numbers. I've seen head gaskets leak without any indication on a compression test, but show up in a cylinder leakage test.

One more possibility. There is coolant in the throttle body, and sometimes they leak when cold and seal back up when warm.

vss

@fasteddy: To my uncalibrated nose I'd say the exhaust smell is much more fuel/oil than sweet. I'm kind of thinking with the age/mileage of the engine of just going ahead and doing a top-end refresh -- pull the heads and have a machine shop do a valve job, build myself a home-brew injector cleaner and clean the injectors, clean out the intake plenum with some BrainKiller stuff (Berryman's B12) and put it all back together and see how it runs, but I'm trying to get a bit more information first. When you mention the "cylinder leakage test" you are talking about a leak-down test, and not the previously-mentioned radiator pressure test, yes?

@mxmikie - Vss? Variable Shutter Speed? VANOS super sport? Vogon Space Ship? Please elaborate <img src="/forums/images/graemlins/cyclops.gif" alt="" />

Eric W.

VSS= Valve stem seals

Like this one?

And yes, VSS are the Valve Stem Seals. It is possible they have already gone bad. IIRC, there was some mention of a newer design that last longer but perhaps that's just my wishful thinking. <img src="/forums/images/graemlins/lol.gif" alt="" />

Ah. Valve Stem Seals. now I understand <img src="/forums/images/graemlins/lol.gif" alt="" />

Actually, I was thinking more along the lines of this one <img src="/forums/images/graemlins/kewl.gif" alt="" />

Eric W.

Just thowing this thought out there because you stated you did the seals already..If you valve guides have excessive clearance, I believe that will lead to premature Valve seal wear, as the valve will move around more side to side in the guide, stretching out the seals and their little spring in the process. Just a thought..Like eddy said it could be a number of things.

Thanks, Justice. I assume this is something a competent machine shop would check during a valve job?

Eric W.

Yes, the valve guides should be replaced with new ones with a valve job IMO. There is an improved design that incorporates a snap ring in order to keep the guides from dropping. Ask for those.