Chrysler Repair: 1995 Concorde suddenly running rough and burning oil, head gasket problems, 1995 chrysler concorde

Question
Roland,

I started calling around to mechanics to get estimates on head gasket repairs.  I described the situation to the local chrysler dealer and he was perplexed because the 3.5L engine usually does not develop head gasket problems.  I then set up an appt. to have it towed to the chrysler place.  Before the tow truck came I went out and started the car again.  This time it started easier but still ran rough and poured noxious smelling white smoke out of the tailpipes.  Figuring I was in for some type of engine repair I had it towed in.

After it had gotten to the dealership they pulled it in to check it out.  The service manager called me and said that when they started it there was no smoke? (Typical car gremlins - they manage to perform 3 times in a row for me and go away the minute they see a mechanic).  They hooked it up to the computer and it was sending a fault for the EGR valve - they also noticed that a couple of small vacuum hoses were cracked and needed to be replaced.  This was all done.

The car now runs smoother than it has for awhile and no smoke.  The mechanic said that the EGR valve misbehaving probably would not make the car smoke like I had describe.  I am very glad I did not have to have the head gasket replaced but a little bit puzzled by the white smoke condition.  Any ideas?

Hank

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Followup To
Question -
Roland,

Here is my problem.

1995 Chrysler Concorde 165,000 miles 3.5L engine
Started the car this morning - easy to start but sounded different when I started it - idled very rough - white smoke coming out of the tailpipes - oil is down about 1/2 quart since I checked it 3 days ago - I did not drive and let the car sit for about 3 hours - I tried to start the car again and it was very hard to start - huge puff of white smoke when it finally started - still white smoke coming from tailpipes - oil on dipstick smells a little bit like gasoline - I have an appt. set with a mechanic for monday morning - any ideas on what the problem might be and how much it could cost?

Thanks

Hank
Answer -
Hello Hank,
It has all the "earmarks" of a blown or leaking headgasket on one or the other of the bank of cylinders. Usually it will be recommended that after figuring out which bank is involved (via a compression test of the cylinders) that the head be removed and cleaned and a new headgasket installed.
I don't know the time that is involved (maybe 5 hours?) and the parts (gasket and headbolts) are under $100. If you have a torque wrench and a set of metric sockets/wrenches/ratchets it is a do-it-youself job but it does require some experience and a good set of instructions. It is a good time to have the valves/valve seats serviced at 165,000 miles so you could do that as well. A machine shop usually does that part of the job but I don't know the cost/head. So if you want to keep the car for a long time you would want to do both banks of cylinders to do the valves there as well. If you just want to replace the headgasket on one bank, that would be a less expensive approach to getting you going. If the compression test on the cylinders that were not affected by the leak meets spec ( at least 100 psi, no more than 25% variation) then you might just go for the gasket only.
One outside possibility that I have had success with is to loosen slightly and then retorque the headbolts on the chance that the leak does not involve the gasket actually being torn but rather the bolts being undertorqued which allows leakage between the gasket and the mating surface. So that is something that you or the mechanic could try first and if it doesn't work then remove the head, etc.
This is just an outside possibility that might be worth your while.
Sorry I can't give you better news, but this happens to most engines before 165,000 miles.
Roland

Answer
Hi Hank,
Fooled me! If the EGR valve were open when the car idled (as it is not supposed to do) then I can imagine that the resulting missing and roughness would cause the exhaust gases to have less heat content and possibly mean that the moisture resulting from burning the fuel would have condensed out in the exhaust system to a greater extent than if the EGR were not misbehaning. Then when you started up the engine all that condensation was evaporated and then recondensed when it reached the tail pipe opening. The only difference is that if the head gasket were leaking the white smoke would continue unabated while the motor was running, which is what you described. I wonder if the leak may be intermittant, though I hate to be a pessimist. Thus the idea of torqueing the head bolts might be still worth considering. The loss of oil is a puzzle too. Do you find anything unusual when you check the dipstick, and how does the fluid in the cooling system overflow bottle appear to be (color/odor normal).
Let me know if anything rears its ugly head again. In the meantime I'll consider "no news is good news".