compression test

[loquito]

I had a pre purchase compression check done, at the time I did not know what
the numbers meant. The mechanic said everthing Aokay.
Well the numbers are as follows
#1 145
#2 130
#3 112
#4 145
#5 145
and just like some posts from owners that found old spark plugs in number 6, well the mechanic did not read 6 nor told me and still charged the full price.
Any thoughts on the two low readings, I thought maybe head gasket since the cylinders are next to each other. I am being told Not that!
I don't know, I plan on doing the oil in the cylinder test, any insight or advice any of you may offer me?
Steven

 

[robbie]

You need to have a rest done with #6 included. If the Person who done this test left #6 in when he did the test, it really is not done right and will lead to low compression numbers. If #6 was out why did he not include it? as for numbers New is 175 psi, I would reccommend a rebuild at 120 psi. Also I would not want to see more than 10% difference between the High and Low cylinders. You have over 20% difference. To this is not fine, but a problem. Also not having #6 reading you can not tell what is happening in this cylinder. This person is doing you a disservice by telling you all is OK. You may have a problem in this engine. If you are really intrested in this truck I would suggest getting a second opinion. later robbie

 

[loquito]

Hi robby
to late, already bought and paid for. I am now happily doing
repair projects. I agree with you about disservice, not knowing
without the #6 being done. But can you suggest scored cylider, bad valve, where should I look?
Thaks again
Steven

 

[Beowulf]

Steven,
Run, don't walk, to Mark Whatley's shop and have him do a compression check before you start diagnosing problems. If he suspects a HG, he will very likely suggest a cylinder leak-down test and make your decision based on the results of those tests and other cooling system tests.
-B-

 

[robbie]

After reading several post you have going now. I need to ask what year your truck is you are working on? In the future if you have more than one truck it would be great to see which truck you are working on.
My previous psot was for a 1fz in a 93-97 truck. Where compression for a 91-92 is 150psi. Still the difference between cylinder is too great for me. Mark Whatley in Wasilla is the cruiser guy in AK and can help you out. He should have the equipment to diagnosis what is going on with your engine and may be a resource for part and such to keep you running great. I believe his company is in the phone book. I looked through a current toyota trails and could not find a phone number for him. give him a ring I am sure he can help you . later robbie

 

[mabrodis]

I am not surprised that the roving mechanic said it was A-OK. Most of the 'mechanics' they have do stuff like that just know the procedure, not what to look for, an in reality he probably had never tested another Cruiser before, certainly wouldn't keep up on what to check for, nor could he be expected to, to many cars out there to remember details on them all. Also if the mechanic tells you the engine needs work that's not a happy feeling, most people like that don't want to upset the apple-cart so to speak, if you like the vehicle, they give you the warm fuzzies to buy it..

A friend of mine bought a '85 Mustang in high school, it had a engine swap and got a 7.5L 460ci engine in it, huge engine, but it fit and the swap was done by a shop. Before buying it they had it gone over by a mobile mechanic dude...well a month later they went to register it and the emission system was not there at all, new cats had to be put in, pipes ran, etc...the mobile mechanic company paid for it all since it was their fault, they should have caught everything, but just goes to show they don't know everything.

I had my Cruiser semi-inspected, not any compression tests or anything, but put up on a lift and looked at. If I was really worried I would have had an actual Cruiser shop do a inspection (Christo did the looking with me), also what I would do if buying a used BMW, have an actual BMW shop do a inspection, since they know what to look for, I (nor most mechanics) wouldn't have a clue what to check.

Just my $0.00 worth..
Mark Brodis

 

[lovetoski]

Related question - no intent to hijack - what tool is used to do a compression test on the 1fz-fe? My screw-in compression tester isn't long enough. (OK, it's short, but it works great - every time - I swear!) I've found the "pressure seal" type compression tester with a long enough stem, but was told that they are less accurate.

Thanks all.

 

[robbie]

Screw in type with a long rubber hose. I have used snap on for over 20 years. Sears has a good one for a decent price. Screw in is the only way to get a consistant reading. the hold in ones will typically lead to less then trust worthy reading. The long rubber hose I have is in two sections with about 24 inches of hose. later robbie

 

[IBCRUSN]

If you really want to get a good idea of the cylinders condition have a mech do a differential compression test, or what the automotive guys call a leak down test. Since it's done statically with the piston at TCD you can easily find out where the leaks are coming from, ie. rings or valves.

I work in the aviation field and on the piston engines this is the best way to assess a cylinders overall condition. The gist is to get the piston at TDC set your input psi at 80 and read the second gauge. On aircraft anything less than 65/80 or 20% is cause for concern. More importantly as robbie pointed out, you want all six cyls. to be about the same +/- 10%. If you have any other questions let us know.

Good luck with your new wheels.

Kris

 

[landtoy80]

Can the 1FZ have stuck rings?
I had one low cylinder on the 2F motor. I put some SeaFoam in the cylinder over night and turned the motor over with the plug out to get the stuff out. The compression went up and stayed up.

 

[robbie]

Yes a 1fz can have stuck rings, I have seen two engines with this happening, usually with the rings stuck out. Pushing the rings into the cylinder wall creating a real nasty wear area at the top. later robbie

 

[IdahoDoug]

You didn't get a compression test here. You paid for an "attempted compression test". How incredibly unprofessional to even charge someone for it, let alone not tell the owner up front they had a problem and could not get one cylinder tested. Would you pay for a guy to test one half of your body for cancer and be content with that? Yowza (shaking head).

DougM

 

[loquito]

Thanks Doug
I agree with you fully!!!
Steven