My '88 4 cylinder 4-Runner keeps on fouling out the spark plugs. I have gotten the spark plugs fixed a couple times, but each time it will start and run about 3 times, and then all of a sudden will have no power and will be puttering along until it finally gives out. I had somebody mention that there might be a head gasket valve that is cracked or leaking (not sure of the lingo here). It is a great vehicle that I want to keep driving…but for the time being, it is dead in my driveway.
Compare the look of your spark plugs with these photos
and post back with which one they match.
Also, are they all the same?
There are a lot of possible causes for sparkplug fouling. Most have to do with burning oil. How much oil does the engine use?
Have you been losing coolant? The “somebody” was alluding to a blown headgasket, but your symptoms are not typical of this condition as I understand your post.
Carb or fuel injected engine?
The car hasn’t really been burning through oil, although I did get it changed not too long ago and it is already very black. The car has been losing coolant like it’s going out of style. I thought that was due to a cracked radiator since it had been overheating all the time as well (when it was running). I had to add coolant pretty much every other time I drove it.
I’m on my way to check out the spark plugs…
“The car has been losing coolant like it’s going out of style. I thought that was due to a cracked radiator since it had been overheating all the time as well (when it was running). I had to add coolant pretty much every other time I drove it.”
This new information is very significant.
Coupled with the “no gusto” comment and the fouling spark plugs, I think it is VERY likely that you have a bad head gasket. Take the truck in for a compression test, a leak-down test, and any other test that your mechanic deems necessary to determine if you have blown the head gasket.
Bear in mind that the disappearing coolant has to go somewhere. It is apparently being burned very rapidly in the cylinders, based on the rate at which you have to add coolant, so I predict that the very expensive catalytic converter will be the next thing to go if you do not fix this right away. And, of course, if the coolant is also getting into the crankcase, the engine will not be long for this world. In other words, you cannot afford to delay in getting this truck to a competent mechanic.
I know that the head gaskets on '90-'95 4Runners are a major problem, and in fact, Toyota has (or had) a policy of replacing them (free or reduced cost), even on high odometer mileage vehicles. Whether this problem dates back as far as '88, I don’t know, but if I were you I would supply my VIN to a Toyota service department and inquire about “service campaigns” for the head gasket on this model. It is very unlikely that they will do anything for you on a 20+ year old vehicle, but it doesn’t hurt to ask.
If Toyota will not help out with the cost of repairs, then you have to decide how much money you are willing to spend on keeping this old vehicle going. Check its book value, and that might help you to decide how to proceed.
Wow…thank-you so much for such a comprehensive response! Now at least I have a direction I can pursue. This has been very helpful!
Please post back with the results of your mechanic’s evaluation and also tell us what the dealership had to say about a “service campaign”.
Good luck with the whole process.