5VZ-FE Cyl 4 Low Compression

Greyhome

Greyhome

Member
Alright guys, I've had my '01 limited for 7 and a half months now and I love it.

For the past few months, I've been chasing a rough idle due to a cylinder 4 misfire. I replaced plugs, wires, coil packs, and cylinder 4's injector.

I just moved to RVA to start a new job and don't have the time to do work myself anymore. I got a compression test done and #4 read at 80psi. All other cylinders reading 130 (I know 130 is low, but everything I've read says consistency is more important than high compression). She's got 193k on her - I've put 13k on since January 1.

So now it's time to figure out if it's a valve, worn piston ring, head gaskets, or something worse.

I'm 23, 3 weeks into a new job and getting married in 4 months. This car has to stay alive and I'm keeping it.

Any wisdom, thoughts, advice, good mechanics in Richmond, for a young guy about to drop a lot of money on a shop to dig into his favorite (and only) cars engine?

Cheers, you guys have already been a huge support since I got the 4Runner.

Graham



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If the #4 cylinder was at 130psi give or take 10% you would be OK. The engine with those low numbers seems like it is rather tired.

Losing any coolant?

Since you have run the compression test, you need to perform a leak down test. I'd also rent a coolant tester from the big box stores IF you are losing coolant.
 
Do a leak down test. You can buy the tool at Harbor Freight for cheap.

I hate to say it, but I would take a wild guess that you have a cracked head on that side, or possibly a bad head gasket.

Do the leak down test, then think about picking up a JDM motor to throw in there if it fails...

I know everyone thinks these motors are bullet proof, but cracked heads are more prevalent than anyone will admit. Here is but one example:

http://www.toyota-4runner.org/3rd-gen-t4rs/235649-headgasket-fun.html
 
Last edited:
Did you hold the throttle wide open and have all the spark plugs removed and a 10a battery charger on the battery for the compression test?

I would check valve clearance first with your milage


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I had a shop do the compression test so no specifics on if it was done that way unfortunately. Leaving it with a trusted shop today to get a leak down and hopefully see what's up. I'll keep you guys posted!

Meanwhile scrolling through CL for a donor engine...


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Pray it's a tight valve. And low numbers on the other cylinders were because the shop left the throttle at idle.

Is 01 drive by wire?


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Well guys, the word is in. The leak down test revealed a compression leak at the exhaust valve. So I'm gonna take some time to figure out what the next move is. But I don't think I can afford the 2k for labor and then parts to fix it. The motor swap idea is cheaper but not by much. At least not quoted by the shop that did the leakdown.

Let me know if you guys have any thoughts or ideas....or if someone has a donor motor....or wants to buy a car that needs a new motor. *sigh*
 
Greyhome said:
Well guys, the word is in. The leak down test revealed a compression leak at the exhaust valve. So I'm gonna take some time to figure out what the next move is. But I don't think I can afford the 2k for labor and then parts to fix it. The motor swap idea is cheaper but not by much. At least not quoted by the shop that did the leakdown.

Let me know if you guys have any thoughts or ideas....or if someone has a donor motor....or wants to buy a car that needs a new motor. *sigh*
Click to expand...

You can continue to drive it with a bad exhaust valve but it's not going to get any better and will only continue to get worse. What you have to be worried about is the valve breaking off. It is either burnt or there is carbon buildup on it not allowing it to close properly. If the valve breaks off it will go down into the cylinder and will be crushed by the piston which will cause a lot of other mayhem inside the engine. So you might make it until you can get it repair or you might now. $2k in labor seems a little steep to simply remove the head and go get a valve job done on it and put back on. However, I have not have to break into my motor yet so might be.

You may want to consider selling it as is. I frequent the Richmond CL and there is a smorgasbord of 4Runners on there at all kinds of price points so you can replace it without a whole lot of searching.

Find an engine out of junkyard might be a solution as well but you only save money if you do the work and with a used engine you may well be buying someone else's problem.
 
Exhaust Valve Pics

Thank you to each of you for responding. After talking with family and my fiancé, I decided to do the work. I ended up getting a valve job done on cyl 4 and cyl 3, a timing belt & water pump (had 84k miles on it, figured while I was down there), head gasket set, head bolts replaced. While that'll be something I pay off over time, I sure am glad to have it done.

And, now I have an excuse to keep the ol' girl for the next 200k miles at least! :cheers:

Anyhow I thought I'd share the photos of the exhaust valves just for everyone's interest. The larger crack is #4's exhaust valve, the other is #3. Apologies for big photos!
 

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1995 Toyota 4Runner V6 Petrol/LPG - low vompression in 2 cylinders

Hey everyone,
we own a 1995 Toyota 4Runner V6 (Petrol/LPG) since February this year and bought it for our travels through australia.
The enginge never accelerated well what we didn't notice while the test drive in the city ...later we thought it's just because it's old.

A month ago we had a backfire, had it towed to a garage and had to change the airmassmeter.
After that was done we had the problem several times that when we tried to get the car running in first gear we had to push the gas a lot - if not the engine just went off.

A week ago we the engine overheated after only 5 minutes of driving. We pulled over and had it towed to a mechanic.
(It's the contractor garage of the RAC - a neat volvo garage that we don't feel to comftable with)
They needed 3 days to do a compession and co2 test and then told us our radiator has a leak and we have only 50% compression in 2 of 6 cylinders (they said they have never seen something like that before) and therefore we need a new engine and a new radiator.

For 6 days they've been looking for an engine and called us today that they found one.
(Now they added that we also need a new timing belt and a new waterpump...all other mechanics always told us that our car is in really good conditions)
Costs are around 7.000$ which we can't afford as backpackers.
If we won't do it they said the car can only go to a scrapyard.

Our question now: is it possible to only change the radiator (and maybe waterpump) and keep on driving with the low compression. Even though it's slow and needs more petrol. We have 3.000 km to go to our destination which is Sydney.

We really hope someone can help us and give us an advise. Thank you so much for your answers!!
 
FrederikeundMarian said:
Hey everyone,
we own a 1995 Toyota 4Runner V6 (Petrol/LPG) since February this year and bought it for our travels through australia.
The enginge never accelerated well what we didn't notice while the test drive in the city ...later we thought it's just because it's old.

A month ago we had a backfire, had it towed to a garage and had to change the airmassmeter.
After that was done we had the problem several times that when we tried to get the car running in first gear we had to push the gas a lot - if not the engine just went off.

A week ago we the engine overheated after only 5 minutes of driving. We pulled over and had it towed to a mechanic.
(It's the contractor garage of the RAC - a neat volvo garage that we don't feel to comftable with)
They needed 3 days to do a compession and co2 test and then told us our radiator has a leak and we have only 50% compression in 2 of 6 cylinders (they said they have never seen something like that before) and therefore we need a new engine and a new radiator.

For 6 days they've been looking for an engine and called us today that they found one.
(Now they added that we also need a new timing belt and a new waterpump...all other mechanics always told us that our car is in really good conditions)
Costs are around 7.000$ which we can't afford as backpackers.
If we won't do it they said the car can only go to a scrapyard.

Our question now: is it possible to only change the radiator (and maybe waterpump) and keep on driving with the low compression. Even though it's slow and needs more petrol. We have 3.000 km to go to our destination which is Sydney.

We really hope someone can help us and give us an advise. Thank you so much for your answers!!
Click to expand...

Low compression won't kill your engine. It sounds like you might need to let the old 4Runner die once you get to your destination... but if you are driving some long stretches of road with little to no assistance nearby it could be a recipe for disaster.

You could try and fix the radiator and move on... but it's unknown if it will hold together.
 
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