QuestionThanks for the trouble shooting start I will look into this tomorrow. I remembered I installed new bosch platinum plugs about 4,000 miles ago, however, I did not replace wires. There was a noticeable difference with start up. Could these plugs cause "hot spot" in the engine block? I have been reading about the 3VZE engine... what a mess, it sounds like head gaskets are an issue.
A couple other noises that have concerned me are one a bearing run out noise? I thought maybe it's a pulley but all the belt pulleys run smoothly, w/o any side-to-side play- I made a note of this after just replacing all the belts. One major symptom/problem is a out-of-balance or vibration that occurs at a low RPM, I can resolve it quickly by accelerating or decelerating depending on the intensity. I am getting a lot of suggestions I just want to take a clear cut, logical approach to solving this issue, like I said earlier it's a great truck, and I have read of people getting over 250K, I currently only have 117K, but those miles a questionable. Thanks again for your prompt response.
Josh
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I bought this truck about 8000 miles ago- great truck. Since purchasing this truck I have performed owner's manual maintenance. There have always been noises under the hood, which I have tried to trouble shoot from the beginning. The noise I heard, and what I thought to be the problem, was coming from the belts. I thought it could even be one of the pulleys. 2 days ago a slight ticking sound started. Today, after driving 20 miles, I lost full power and can only reach a speed of 50 mph. There is lack of power going up hill, and rough idle @ stop lights. There is no white smoke, my temp gauge remained the steady, there is a decrease in oil pressure. Can you advise me on what to trouble shoot?
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It sounds like there is an engine misfire, I would remove and check the spark plugs and the spark plug wires and distributor cap rotor, tne lack of power may also be due to a loss of cylinder compression so I would also recommend having the engine compression tested to eliminate it as the cause, if the engine compression is good then a routine tune up will probably cure the problem
AnswerI used to own a 1990 4Runner myself, yes, there were some problems with headgaskets and toyota had an ongoing service campaing to replace the defective gaskets, not sure if that's the problem here but almost all these engines have either been done or are now out of the warranty because it was a limited service campaign, there was another common problem with main bearing noise, this is the low speed noise/vibration that is present at idle and under slight load conditions, my 4 Runner did the same thing, the solution is to replace the main bearings with the correct size bearings, of course this is a major repair so the best advice I can give at this time is to not try to pour in good money after bad and create a bottomless money pit, if the rest of it is in good shape and you really want to keep it I would suggest making a one time investment and either try to find a good used engine( they are not plentyful)or a remanufactured unit, in either case it will probably cost about $1,500 to $2,000 for the engine alone.
