Dear CarTalk
We have a beloved 1995 Jeep Gr Cherokee 4L that was our first new car! We have babied it for many years. It now has 173k on it. We took to local Jeep dealer to get all RECALL items taken care of and to have it checked out completely. It was pinging on acceleration and hvac wasn’t working. They kept it 5 months and finished all recall stuff and replaced the ENGINE TEMP SENSOR. They also recommended a new trans and a new AC. We passed. ($800) Then we got new BRAKES ($775) and new tires. Since my niece wants it; and she loves it like we do; we took it to an honest transmission shop. They said trans was fine just
needed oil pan gasket, rear main seal and an elec engine diag because trans and engine were not speaking to each other ($1200).
No our JEEP is home; sits in driveway all week. When we start the car on Saturday we still have WHITE SMOKE then after driving awhile it goes away.
Does not leak oil; does not need coolant; has NEVER over heated. Engine sounds great and it runs great.
Had it tested for head gasket a couple of years ago and they said pressure was fine. We have never had to put coolant in it. The dealer and other Mechanics said nothing. Any ideas?? We would like to have it in sound mechanical condition before we hand it off to my niece.
THANK YOU so much for your help!! 
If this niece is a young person than a 21 year old jeep with 173000 miles and mystery problems would be a lousy gift. Use it for trade on a newer vehicle that is much safer.
Why in the world did this dealer keep the vehicle for 5 months?
The pinging is likely related to an EGR system fault and that really needs to be fixed. Chronic pinging and severe enough pinging can lead to engine damage; especially during sustained high speed driving or mountain terrain driving.
It’s assumed that when smoke is involved that black means a rich fuel mix, white is engine coolant, and blue is oil. That is not always the case as there are variables involved.
Assuming this is not a coolant leak into the combustion chambers and the cooling system is fine with zero leaks you might consider valve seals and/or engine oil coking in the valve train area.
There is no test for valve seals. That’s a replace and pray type of fix.
There are drain holes in the cylinder head which allows engine oil to drain back into the oil pan.
Sometimes oil coking occurs and things sludge up in the valve train area and plug the drains up.
This allows oil to pool around the valve guide bosses/valve seals and when the engine is started some of that pooled oil is inhaled.
Removal of the valve cover could determine this and if applicable the drain holes can be cleaned out.
Hope that helps in some way.
Try changing the PCV valve out. You may be sucking oil into the engine.
Yes @Cougar, it may be the PCV. On the early Cherokee 4.0L I6 there was no PCV valve. The engine had a small plasic tube that metered engine venting but the plastic tube could be pushed down until it was resting in liquid oil puddled on the head between valve guides. When the engine is cold the oil drains off slowly and puddles up easily but when fully warmed up the oil drains off the head too quickly to be sucked out into the intake.
“Why in the world did this dealer keep the vehicle for 5 months?”
I would have a very hard time trusting the work of a shop that was…allegedly…working on a vehicle for 5 months.
Besides if it took 5 months to fix it why would you let someone you knew have it.
The fuel tank recall supplies aren’t always available/limited supplies and the other recalls are very old, parts may not be available. It would be reasonable to take the vehicle home while waiting.
You are 100% right Rod. This vehicle does not have a PCV; I have had to tell many mechanics that over the years. Engine runs great and sounds great now but I will have the venting checked and the valve covers checked. I agree there should be coolant involved somewhere but we aren’t losing coolant. Smoke goes away after driving a few. Does sitting all week contribute to the smoke too? Great info from everyone!! THANKS !!
Yes. You are right. The dealer had to do ALL RECALL items and they couldn’t find all
of the parts. Thanks again!!
I have performed a number of those brake/shift interlock recalls. That recall is more than 18 years old, I’m surprised the parts are still available.
The delay is understandable then and I’m also surprised that they could even come up with the parts.
I will reiterate that the fixation on coolant being the cause of the smoke may not be correct. It could be oil related for the reasons I mentioned earlier.
White smoke out the exhaust pipe when first starting the car may be normal, as long as it goes away once the engine is warmed up. That may just be water vapor, a normal product of combustion. One further measure to make a determination whether this is a problem is how frequently you need to add coolant to keep the radiator and coolant tank topped off.