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Any hope for a '91 Toyota pickup that started billowing white/blue smoke?

Please, please, please someone tell me this is going to be an easy repair that costs less than $1000. Cause if it costs more than that or if I need a new car I am in serious trouble.

Last night I was driving home, and the truck started to feel like it was losing a little bit of the power it used to have when I step on the gas, and it was billowing white/blue smoke (a LOT of it) and it smells like burning oil. The engine has been knocking for a while, not too bad but enough to notice. I have been trying to keep up with the oil leak and I’ve been giving it premium gas to see if that helps.

It is a 1991 extended cab v6 pickup with 206,000+ miles on it. I know it has problems with its rear main seal (I don’t know what that is, but that’s what my guy told me).

I am such a whimpy girl that when it did it again this morning I started to cry, and my husband being the big tough marine that he is can’t handle crying so he told me “well maybe it isn’t as bad as it looks…or smells”, and then went to work.

My car guy can’t look at it until he gets off from his day job tonight at 5, and I want to be prepared for what he tells me.

I rode my bicycle to work, and if the truck dies I can do that for a while, but this is Utah and I’ll need more closed in transportation come October. So if it does die, any suggestions on a reliable, cheap vehicle that can withstand very hot summers and very snowy and cold winters?

This Is Going To Be An Easy Repair That Costs Less Than $1000. Feeling Better ?

Good. Well, at least you got a couple of seconds of relief before the bad news hits.

The knock doesn’t sound good (neither does the smoke), but let’s talk about the smoke. It should be pretty easy to check the vehicle’s PCV system to be sure it’s not plugged and that the PCV valve rattles when removed and shaken. The PCV valve is probably quite inexpensive to replace. It’s a maintenance item. If it plugs up, the truck can smoke.

None of this will probably help, but it will give you something to do to take your mind off the inevitable.

Is it too late to join the Marines ?


Thanks. I am car illiterate, what is a PCV system? And yes it is too late for me to join the Marines and my husband is getting a medical discharge. sigh If joining up were an option for me I just might do it, because my company is laying off and I might not have a job next week. Same old recession blues song. I will be borrowing my dad’s '51 willys jeep until I can fix the truck or find something suitable…although if you could see it, you might understand why walking would be better.

The PCV is the Positive Crankcase Ventilation system, which was mandated as the first pollution control device on gasoline engines, beginning in 1963. Rather than allowing “blow-by” fumes from the crankcase to escape to the atmosphere, the fumes are routed to the intake in order to be combusted by the engine.

If the PCV valve (or the PCV hose) is clogged, it is possible for oil consumption to increase drastically, and for oil leaks to take place, so it is a good idea to check this out. If you can locate the PCV valve (likely located on one of the valve covers), pull it from its grommet, and shake it. If you hear it rattling, that is a good sign. If it is silent when you shake it, that is a pretty good indication that it is gummed up. It is fairly easy to clean the PCV valve and the line leading from it to the intake by shooting some specialized solvent into it while the engine is running. However, it is also probably the cheapest part on your truck, and for about the same price as the solvent, you can replace the PCV valve.

All of that being said, I have to say that I am not really optimistic about the PCV system being the source of your problems. In addition to checking the PCV system, I would suggest that you look at the motor oil in order to see if there is any evidence of coolant in the oil, and that you also see if there is evidence of oil in the coolant. If you do find these situations, that is a strong indicator of a breached head gasket. Coolant-contaminated oil will look like a chocolate milkshake. Oil-contaminated coolant will leave a black, grimy line at the upper fluid level in the coolant overflow reservoir.

If you do have a breached head gasket, as I suspect that you do, the repairs will probably exceed the book value of the truck. Hopefully, I am wrong about a breached head gasket being the source of the problem.

Sorry for some gloom and doom, but I think that you do want to deal with the possible realities of the situation.

Thanks for the assessment, at least now I can be prepared for whatever happens. Thanks for the explanation, it makes a little more sense now. I have attached a photo of my temporary replacement vehicle, a '51 willys jeep that belongs to my dad…it beats walking, but not by much.

You’re Welcome. There Are Several Sites That Discuss Positive Crankcase Ventilation Valves / Systems.

Click this link and go to one of them:


Knocking, sudden billows of smoke, and loss of power. This does not sound like a PVC valve to me. It sounds like something worse. Knocking is caused by worn out rod bearings, which at 206k is not unlikely. If it has gone on too long, it also can lead to worn crank journals. Not good, but fixable, (the crank will have to go to the machine shop). The smoke is caused by oil in one or more cylinders, caused by, worn out valve seals, and or, worn out rings (toyota truck cylinders hardly ever wear out much at all), possible head gasket failure, PVC valve clogged causing increased back pressure in the crankcase and more oil getting past the worn rings. It could also be broken rings, or a cracked piston ring lanse. If it is worn out valve seals, the loss of power and increased smoke (oil burning) could be caused by carbon build up on the valve seats, and or fouled plugs (can cause loss of power). What you need to do now is get your car fix it guy to do a compression test, because that will tell him just about all he needs to know. Make sure he keeps the plugs in order, and checkes them for indications of engine condition. and good luck with keeping your job, cause it sounds like you are in one of those, one thing after another periods of life that we all have too much experience of.

I hope you keep your job. I’ve been laid off 3 times in my life and it really sucks starting over. You have my sympathy.

I have to say that I doubt it will be something simple based on the symptoms you describe. If the rest of the truck is in good shape, you may be able to get a low-mileage, good condition engine from a salvage yard and have it installed. This will be cheaper than rebuilding yours, but will likely be about twice your $$ limit unless your mechanic is a true saint. (no Utah pun intended)

It may be time to move on to another vehicle. Good luck and I hope it turns out alright :slight_smile:

FYI: PCV Valve = Positive Crankcase Ventilation Valve. PVC Valve = PolyVinyl Chloride Valve.
Also, A Knock Can Be Caused By Other Things Besides Worn Out Rod Bearings.

It doesn’t sound like a PolyVinyl Chloride Valve to me, either.

Thank You For Your Attention In This Matter.


Thanks everyone for your answers, it has been very informative. I limped the truck in to my mechanic and he said that the problem was the head gasket, he said antifreeze was leaking into the cylinders. I tried starting it up one more time and it made a noise like that thing that tire shops use to put lug nuts off and on. Said it would be too expensive to fix or replace and to just get a new car.

I’m actually really depressed about it because I LOVED that truck. I went used car shopping and the only thing I could find in running condition in my price range was a '72 F-250 for $800, but it needed about $500 in repairs before it would pass inspection. My loaner vehicle got a flat tire this morning so I rode my bicycle to work. It is going to be a really long summer on that bike.

I’m really sorry to hear that I was correct about the head gasket being the source of the problem. I was really hoping for your sake that it would be something less serious.

Since you are now in the market for a used vehicle, I was to stress the importance of not rushing into any purchase. Take your time, try to get maintenance records (likely not possible with an older vehicle, but, if they are available–great), and have your mechanic inspect anything prior to purchase.

Good luck!

I actually now have 3 really nice mechanics who are friends of the family scouting for used cars for me. Almost all of them said something along the lines of “We’ll find you a nice little honda/toyota/nissan that is safe and gets good gas mileage.” I’ve gone and looked/driven a few cars in the classifieds…and it is really depressing. I keep telling myself that I’m from hearty pioneer stock and to suck it up. Hopefully with all the help I’m getting we can find something decent.

ha ha ha, very funny, one little slip of the fingers on the keyboard, and now you think I am an ignoramus. Geeze, waht a wonderful life.

ok ok, two slips of the keyboard. (actually I almost always get this one wrong, its an intelectual thing, you wouldn’t understand.)

over a grand for a head gasket replacement? seems a little high to me. the gasket set is about 100 bucks, and a new set of head bolts, possible machine of head surface, might as well re-seat valves, another 100 bucks or so. Labor? could be 4 to 6 hours shade tree. I wonder what else is wrong that it cost so much.

I guess I was trying to start it and I seized the engine (not sure if that’s the correct term), and there was a problem with the radiator and the rear main seal (not sure if that’s the right term either). It was a laundry list.


Let’s not forget the “fallout” of head gasket problems, including poor lubrication of engine parts due to coolant dilution of the motor oil. The OP did note that her mechanic stated, “antifreeze was leaking into the cylinders”. If that was happening for more than just a few days, severe damage was likely done–especially considering that the engine had been in service for 19 years/206k+ miles.

The OP also stated, “I tried starting it up one more time and it made a noise like that thing that tire shops use to put lug nuts off and on”. When an engine sounds like an impact wrench, there is A LOT more wrong with it than just a breached head gasket.

Impact wrench, thank you for letting me know what that is. Yes the noise was so loud and so abrupt that I flipped the key off, jumped out of the truck and ran because frankly I thought something might blow up. But I am a dumb car-ignorant girl, it made my mechanic and my brother in law laugh. (I also get freaked out when jump starting cars, I’m always afraid a spark is going to go where it shouldn’t, even though I know the chances of that happening are like 1 in a million.)