cashmoney00

Is it possible to have a blown head gasket on an engine that doesn't burn oil, doesn't hesitate, doesn't miss, doesn't smoke, has no coolant in the oil, no oil in the coolant, starts first time every time, and other than an isolated overheating incident (which seems to have been taken care of and hasn't over heated since) runs flawlessly except for having no power and crappy mileage? My 4runner won't maintain 80mph (legal speed limit on the toll road) on flat ground and is getting about 10mpg.

Plugs, wires, pcv, fuel filter, air filter all changed last week. MAF, TB, IAC all cleaned last week. All cables tightened to remove slack. Timing has crossed my mind as it's an absolute dog between 1500-2500 and then takes off like what I think normal should be. I stomped on it from a stop and it was doggy through those rpms and then took off and shifted promptly and crisply at 5000rpm. Only thing I've got left to do is fluids (this weekend) seafoam the intake (I'll sacrifice the new plugs), and O2 sensors (no lights on the dash). Beyond all of that and a compression test I'm out of things to try. Is there an easy way to check and make sure the timing is good or just a good old fashioned timing light? Timing belt and water pump were replaced last year and the engine has 218k miles on it.

Long first post I know but I'm trying to get as many ideas to test and try before I tear the engine down. Thank you.

And since my signature isn't showing:
2000 Limited 3.4L 4x4 - 265/75 Nitto Terra Grapplers - Bilstein 5100 front struts - Eibach 3" front springs - Superflex Rear Springs - Bilstein 5100 Long Travel rear shocks

wyoming9

iTrader: (1)

Has it always run what you think is poor??

Might be the timing belt was not done correct if it started then.

I have never driven a automatic so can`t compare.

Then I don`t think I ever drove that fast for a few years.

I do know my Engine builds power about 1800 rpm and up.

As far as timing that is all done through the ECM

cashmoney00

Hard to say. I've only owned it for two weeks and the first week I drove it home and it sat parked while I gave it a tune up. This week was the first week I've really gotten to drive it a bunch and at highway speeds. You can feel mine get sluggish around 1500-2500 and then power picks up from there. Engine is very quick to respond when taking off and then it hits that point and it slows and then it picks up again from there. So much so that I'm having to drive around those RPM's so I can actually accelerate or lock out OD completely to keep the RPM's up. Of course those RPM's are exactly where the motor sits when I'm between 70-80mph which confirms my thinking that something is wrong there which leads me back to timing. But engine timing is controlled electronically and since there aren't any lights on leads me to think it's not a crank or cam sensor so perhaps the valve timing is off from when the timing belt was done.

cashmoney00

Starting from driver front and going back:
150
145
155

Passenger front to back:
155
155
145

She's a tired engine that's for sure but she ain't dead yet.

mattbatson

just an fyi.
I am 99 percent certain I have a blown head gasket or cracked head on my 97 with 3.4
losing coolant quickly, white steam out exhaust for a couple of minutes on startup, etc...


but power is fine...normal


had the truck over 11 yrs, and would notice a difference there....

vital22re

iTrader: (2)

Ideal compression should be 175-190. I would verify that the cam timing is correct. the computer controls the ignition timing. I would also grab a scan tool and check what the ECT sensor is telling the computer the temperature is. These can read that you're only at 90 when you're really operating at 190. I would also check the TPS reading.

Besides that, what plugs and wires did you use? what oil do you run?

This may be a good idea as well. Pull the plugs , and put about 2 tables spoons of marvel mystery oil in each cylinder. Then let is sit for 30 minutes, turn engine over by hand 2 turns. Let it then sit for an hour and turn it again. Its best to let it soak over night and before starting it, crank it with the starter to clear out the cylinder and put plugs back in. I hope you went with NGK or DENSO dual ground plugs NOTHING ELSE. What this does is free up the rings on the pistons. If the oil used was just standard dino and not changed frequently enough, it cakes on the rings and cause loose seals to the cylinder walls. I've had this trick work a couple times on bringing compression up slightly.

cashmoney00

I used the NGK dual ground strap plugs. No worries there.

Replaced tps yesterday with no change. All mobil 1 in everything but the transmission.

I'm fairly confident this is either timing or fuel related. Is there a write up somewhere about checking valve timing? Or just follow the procedure for replacing a timing belt?

I'm going to take it to a shop here in a couple of weeks and let them do a leak down test, fuel pressure test, and run a scanner on it.

The engine doesn't smoke, doesn't miss, doesn't hesitate, and doesn't burn oil. Found out where my coolant had been going. Heater core is busted. Awesome. At least it's summer time.