I bought a 1994 Isuzu Trooper about a month ago as a project just so I could learn a little more about cars and so far am loving it; however, there are a few issues that are worrying me. Oh yeah, it has 214,700 miles on it as well 
1). I recently noticed that upon starting the car, a puff of white smoke emerges from the tailpipe, but quickly goes away and doesnât smoke when driving. Naturally, I googled âwhy does my car smoke when starting?â and I read that it could possibly be two things: the piston rings need to be replaced and will likely cost more than what I paid for the car ($900) or could be a problem with leaking valve seals which is less expensive but still probably more than what I paid for the car.
I guess what Iâm asking is if these two theories are viable, or if it is something less serious and if it is something that I can repair myself with a manual and the limited knowlege I have.----Although I rebuilt a briggs and stratton small engine successfully using only the manual last summer for fun!â
2) I noticed that the car smells like something is burning after being driven for a while. It almost smell acidic but could possibly be oil from the minor oil leak dripping on something hot under the car? But i personally think it is more along the lines of a hose or belt.-Any theory you could give me on this would be helpful as well even though the description is very limited.
thanks to all in advance!
Blue smoke at start up would relate to the answers you got on google. White smoke and the acid burning smell is antifreeze burning in the exhaust. Iâd suspect a bad head gasket, cracked head, or (hope not this) a cracked block. Anyway you look at it, Iâd say you have a potential serious problem.
It could just be oil leaking from the valve covers causing the smell, You wanted a project car, wish granted, it is a learning experience, not much to loose by trying the repairs yourself. See if you can find the source of the smell, worry about the white puff of smoke at start up later
I suspect an oil leak, probably valve cover gasket, for your burning smell. The puff of white smoke may or may not be a problem. Many cars emit a puff of white smoke on initial startup due to the slightly richer conditions required for startup. Monitor your fluids to detect any fluid loss. If you are going through a lot of coolant, your puff of white smoke is definitely cause for concern. If youâre not, it is not a concern and is normal, particularly for an old car with over 200k miles on it.
Burning oil can definitely look white against some backgrounds. Try having someone else start it while you stand by the tailpipe to check for bluish tint.
You need to Google more precisely. Go to:
This will give you an idea as to what might be going on. There are several potential causes, including the previously mentioned head gasket.
But you certainly donât want to start to tear into replacing a head gasket if that is not your problem. However much you want to learn about cars.
The question is what is leaving your tailpipe when you start the car, water vapor or burnt oil?
You can tell by checking the tailpipe. Run a finger around the pipe while it is cool and see what the soot from the pipe looks like. If it is oily and black, then in fact you are in need of some kind of major repair. If it is white and dry, you are in good shape. In this case your car is just burning off water while starting that has naturally accumulated in your exhaust system. This is most noticeable in cold weather.
If the soot is oily and black, try having someone else start the car and put your nose near (not at) the tailpipe so you can smell the puff of white smoke. We humans donât have a great sense of smell but you should be able to tell if the smoke is oily and wet, or just burning oil (transmission fluid).
Next, check your fluids. Which are you losing, transmission fluid or radiator fluid?
As far as this part of your question is concerned, I bet the car has some miles left on it unless it is in fact a bad head gasket. If you are determined to replace the gaskets, do both and be sure the rest of the engine is sound before you start. You need to check each cylinder for good compression. Iâd buy a Chiltonâs for your model before I did anything.
As far as the acrid smell goes, it is pretty likely that engine oil is dripping onto a hot surface. But acidic is not a smell I would associate with burning engine oil, so perhaps it is something like power-steering fluid or brake fluid. Again, which fluids missing and need to be continuously replaced?
Hope this helps.
How did you determine that there is a puff of white smoke? If you observed it when someone else started the car, it may not be a problem. During the cooler parts of the year and depending on your local climate, there may be mornings where every car emits some visible steam when first started. And any car with 214K on it might reasonably be burning a little oil.
However, if you observed it in the rear view mirror, itâs probably quite a large puff of smoke and is something that you need to worry about. The most immediate concern would be a cracked head gasket that is shooting coolant into one of the cylinders. Iâd suggest that you monitor the coolant level in the radiator when the car is cold. Be aware that overflow tanks on elderly cars sometimes lose their connection to the cooling system so that the level shown in the overflow tank may be unrelated to the amount of coolant actually in the system. And keep your eye on the temperature gauge. If it starts to soar, stop, let the vehicle cool off completely, fill the cooling system with water and limp home. Youâll be wanting to flush and refill the cooling system anyway after the repair if coolant levels have dropped so low that the car overheats.
Monitor the oil level as well of course.
Itâs been a while since I owned an oil burner, but I seem to recall that going down a moderately steep hill with the engine running, but with your foot off the gas, then stomping on the gas pedal will produce a visible cloud of smoke if the engine is burning a significant amount of oil.
Burning smell? Youâll want to track that down sooner, not later. Problem is that it may actually be something burning that could start a real vehicle fire. Once you know what the problem is, fixing it may be trivial or may not be urgent.
You bought the car as a project car to learn more about automobiles, so Iâll try to answer your specific questions in a teaching manner. I apologize it it comes out a bit lengthy. Here goes.
Yes, piston rings and valve stem seals are both possibilities.
As the engine runs the cylinder walls are bathed with oil. It not only lubrcates the walls and washes them, it also washes away heat. The botton piston ring set, the âoil ringâ wipes the oil off as the piston descends leaving only a film of oil from the oil captured in the cylinder wall honing marks and in the imperfections. This film provides lubrication for the compression rings, which capture the pressures and gasses from the exploding fuel to keep it from blowing by the pistons and polluting the oil (and building excess pressure in the crankcase). If the cylinders are too worn, the rings too worn, and/or the rings too tired (they lose their sideways spring pressure over time), oil can pass into the combustion chambers and be burned.
The valvetrain is also lubricated and after use the oil runs back down through return passages into the crankcase. These seals keep the oil from being drawn into the cylinders when thereâs vacuum there. Vacuum goes especially high when the pistons are pulling air in and the air intake passage become suddenly blocked, like when you take your foot off the gas and the throlltle plate closes. If these seals are shot, they can allow oil to drip onto the backs of the valves as the engine sits overnight. When you start the car, that oil then gets drawn into the cylinders and burning, creating a cloud out the tailpipe in the morning.
Another possibility is simple steam. Gasoline is molecules of hydrogen and carbon bonded together. When itâs surrounded by the oxygen in air and heated, the molecules tear apart. The carbon bonds to the oxygen forming CO and CO2. The hydrogen bonds to the oxygen forming H2O, water. Until the exhaust system warms up, the cooling exhaust can condense in cool weather as it travels down the pipe and come out as a water vapor, a steam cloud.
A steam cloud with an acrid smell usuallly suggests vaporizing coolant. Sometimes smoke can also come from oil dripping onto a hot exhaust manifold.
There are way of testing to determine the cause of yours.
The condition of the rings and cylinders overall can be determined by doing a compression test of the cylinders.
To test for the possibility of burning coolant, a âcompression leakdown testâ can be performed. It puts compressed air in the cylinders then monitors with a gage to see of the cylinder is capable of holding the air. If the pressure doesn;t hold, it may be blowing the air through a hole in the headgasket. That same hole if it exists would allow coolant to be drawn into the cylinders and burned. It would also allow hot gasses to be blown into the water jacket, often causing cooling problems.
Hoses and belts can be easily checked. Hoses should be squeezed, looking for cracking and/or stiffness. A good hose should be pliable with no signs of leakage and no cracks when squeezed. A good belt should have no cracking in the âVâ and no glazing (shiney surface areas).
Leaks onto exhaust manifold of pipes can be checked for with a simple visual. And sometimes a sniff when hot. And a monitoring of fluid levels.
Know that engines can run for years burning some oil, but leaks of coolant into cylinders can be very destructive. Leaks of coolant to the outside world can and often do become engine overheats, so they should be corrected.
How big of a âpuffâ are we talking? Depending on how much cranking is needed to start the engine, it could be unburnt fuel vapor. A 1994 engine with unknown maintenance history probably has some wear, so it probably has worn valve guides too. If it runs well otherwise, you got a good deal and Iâd not worry about it.
You probably have one or more small oil leaks that are seeping and burning on the exhaustâthatâs probably what you smell, but not smelling it for myself, who knows?
Monitor your oil and coolant VERY carefully for both quantity and quality. Report results back here if youâre losing some or the coolant or oil is getting contaminated.
Losing a little oil is no big deal. Letâs hope youâre burning a little extra fuel or oil at startup. This isnât a big problem.