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-   -   Valve Job Deceision (http://www.wranglerforum.com/f210/valve-job-deceision-229214.html)

97Snyder 03-20-2013 09:19 PM

Valve Job Deceision
 
Hey everyone,

I have a 97 TJ SE 5speed. It has been throwing a check engine code for the last couple of months and it has been misfiring. I put my code reader on the vehicle and it did in fact confirm my suspicion of a misfire, Cylinder 1 to be exact. I just did a tune up last spring (Plugs, Wires, Cap and rotor).

I started to tear into the project to find that my distributor was shot and so I replaced it. It ran good for a week and then the check engine light returned.

I bought new stock recommended sparkplugs and replaced the year old ones. The old ones looked clean except cylinder #1. After this it still misfired in cylinder 1 only. I then started the jeep and watched for the spark plugs to arc and found them to be fine. So I then took cylinder 3 sparkplug and exchanged it with cylinder 1 sparkplug in the off chase the porcelain was cracked. This still did not help.

I am know sure that a valve must be stuck of bent. I am expecting a baby in the next few weeks so a new engine is out of the question at least for now and am considering doing a valve job. The 4 cylinder has 177k miles on it and I am afraid that a valve job will cause to much compression for the old girl's rings. Has anyone else done a valve job on these engines with high mileage and had good luck?

Thanks for all the future answers and comments.

Dieselholic 03-20-2013 09:26 PM

I don't think a bent valve would cause a spark plug to fowl. It would do a miss fire. But you would know cause it would not seat correct our open all the way. Also It would make a heck of a noise. If your want to check then it's easy to remove the head. I know my shop charges 100 to go threw the head and check everything. And I have a 6cly.

But i would check injector first. Just switch them around and see if the #1 is leaking to much fuel. It's free and easy to check befor removing a head.

97Snyder 03-20-2013 09:30 PM

Thanks Dieselholic I will check this tomorrow or the weekend and let you know what I found.

97Snyder 03-20-2013 09:34 PM

Oh and I meant a burnt valve not bent My mistake.

Dieselholic 03-20-2013 09:39 PM

Even if you had a burnt valve. That would mean its not setting very well an you would have bad compression in that cylinder. It would cause a miss. But You would know it was missing with out the comp telling you. And loss of power.

Gunner 03-20-2013 09:41 PM

Do a compression check on all 4. It will tell you right away if you have a problem with a valve or ring on #1.

97Snyder 03-20-2013 10:40 PM

I don't think I have a Compression Tool but maybe my cousin does. Ill check both and return with results tomorrow.

97Snyder 03-21-2013 01:10 PM

I took out all of the fuel injectors and they are clean as a whistle. I then moved them around and cylinder 1 is still misfiring. While I was doing this I had the airbox off the throttle body and set aside. While the engine was running smoke was rolling out of the airbox from the return hose that was still hooked up. I did forget to mention that I have an oil leak and have not been able to fix it. I have been just adding a quart whenever it is low.

Also it does not burn oil and appears to be leaking out of a bottom end gasket. I now believe that a drive while low on oil I might have burnt bearings and bushings.

InvisiblePants 03-22-2013 01:39 AM

Re: Valve Job Deceision
 
Quote:

Originally Posted by 97Snyder (Post 3531567)
I don't think I have a Compression Tool but maybe my cousin does. Ill check both and return with results tomorrow.

Call around to you local auto parts store and see if they have a loaner you can use. They will charge a deposit to you credit card and refund it upon the safe return of their tool.

97Snyder 03-22-2013 02:01 AM

Thank you. I have loaned tool before but did not know they had compression tools. Ill call around tomorrow when they reopen.

97Snyder 04-01-2013 07:07 PM

Sorry guys I havent had the time to check compression. However I have the next three days off so Ill check it out and post results. Thanks for your patience and help.

97Snyder 04-03-2013 05:15 PM

Okay, so I had a chance to check the jeep today but wasn't able to do to much..... I changed the cap and rotor in attempt to make sure there was no malfunction there and it was only $20 so not an expensive chance. This did not work. I then checked compression on cylinder one and it wouldnt even budge the needle. I then dble checked everything and tested it again and it again read 0psi. I then put a couple of squirts of oil in the cylinder on top of the piston through the sparkplug whole. I was told that if it showed compression after this it would mean the cylinder walls or rings are shot. I then tested the compression with the same results.

I then watched a video on youtube of how to check the valves at top dead center to see if one is stuck open. I turned the enigne until it was TDC on cylinder 1 then hooked my air compressor to the hose of the compression tester to check for an air leak. This was a negative as well as I could not find an air leak anywhere and the compresser gauge showed no loss of air either.

I am now considering it may be the camshaft is shot as I believe that the intake valve is not opening ever...... making it not to have any air inside the cylinder for combustion......

Any ideas guys??

tailhole 04-03-2013 05:34 PM

Turn the engine over and watch the rockers. That will tell ya if there working or not

97Snyder 04-03-2013 06:08 PM

Yeah that's what I was thinking of doing next

bardb 04-03-2013 06:17 PM

Test the other cylinders too. You may have a leaky connection to the gauge or faulty gauge which will show up as a 0 psi reading on them as well. No sense trouble shooting faulty test data. Since you have a source of compressed air, you should consider a leak down tester as it can help determine the source of any leakage.

97Snyder 04-03-2013 08:38 PM

I plan on taking off the valve cover next to see if it moves when its cranked over.... also how do you do a leak down test? I will have to do a little research and youtube watching to do one of those.

bardb 04-05-2013 12:10 PM

Leak down tester is a different beast. You screw it into the head the same as the compression tester, but you don't crank the engine to compress air. You connect an air supply and read the two gauges on the tester. One is the supply side pressure, the other is what the cylinder is holding. You will have to turn over the engine by hand to catch the valves closed for the cylinder you're on. Apply a little math to determine leakage % or just make sure the supply is the same when testing all cylinders. Shooting a little oil in the cylinder and retesting gives you ring leakage just like the compression test.

97Snyder 04-05-2013 02:35 PM

Quote:

Originally Posted by bardb (Post 3598223)
Leak down tester is a different beast. You screw it into the head the same as the compression tester, but you don't crank the engine to compress air. You connect an air supply and read the two gauges on the tester. One is the supply side pressure, the other is what the cylinder is holding. You will have to turn over the engine by hand to catch the valves closed for the cylinder you're on. Apply a little math to determine leakage % or just make sure the supply is the same when testing all cylinders. Shooting a little oil in the cylinder and retesting gives you ring leakage just like the compression test.


That doesn't sound to hard to do. I will attempt this after I take off the valve cover and turn the engine over to check the exhaust valve. Thanks for the instructions.

Geneticallybroke 04-05-2013 11:16 PM

my bet is on a valve seal

97Snyder 04-07-2013 01:49 PM

Ok so I went and bought a compression tool from advance instead of renting the one from autozone again. I tested all cylinders and the results are as follows:

Cylinder 1: 20PSI
Cylinder 2: 155PSI
Cylinder 3: 140PSI
Cylinder 4: 155PSI

So as you can tell Cylinder 1 isn't producing. However I do not know what can cause that much difference. Can it be a valve, ring, piston, cylinder, valve seal, etc? Also to be noted it does not knock, tick or make any abnormal sounds besides the obvious rough idle from it misfiring.

Can anybody tell me what I should check next?

97Snyder 04-07-2013 04:01 PM

I put a little bit of oil in the cylinder 1 and retested the cylinder to find it increased it to 45-50psi. So Im thinking its the piston rings and I will need to rebuild it, find one from a salvage yard or buy a rebuilt one or sell it.

tailhole 04-07-2013 07:59 PM

Well. You know you have a problem.

It's got to come apart to be fixed anyway.

97Snyder 04-07-2013 09:30 PM

Quote:

Originally Posted by tailhole (Post 3606848)
Well. You know you have a problem.

It's got to come apart to be fixed anyway.

Yeah I know but I am trying to decide if it is worth fixing as the car dealership I purchased it from 4 years ago is offering me $2500 to buy it back as is. If I can find another engine for a decent price I will fix it and keep driving it otherwise I might take the cash and drive the truck around instead.

So..... if anyone know of an engine I can buy just let me know please.

InvisiblePants 04-07-2013 10:28 PM

Quote:

Originally Posted by 97Snyder (Post 3607266)
Yeah I know but I am trying to decide if it is worth fixing as the car dealership I purchased it from 4 years ago is offering me $2500 to buy it back as is. If I can find another engine for a decent price I will fix it and keep driving it otherwise I might take the cash and drive the truck around instead.

So..... if anyone know of an engine I can buy just let me know please.

If you are going to sell it back to the dealer, you could always part it out, may end up with more money in the long run.

97Snyder 04-07-2013 11:00 PM

Quote:

Originally Posted by InvisiblePants (Post 3607468)
If you are going to sell it back to the dealer, you could always part it out, may end up with more money in the long run.

Im debating parting it out but I am a little conserned once I part it out I will not reach the $2500 and then I screwed myself in the foot.

InvisiblePants 04-08-2013 12:06 AM

What shape is the body in? Do you have hard top or soft? Full doors or halfs. What wheels and tires and how much tread is left. Is the frame good? I think you could do it. You might be surprised. Half doors alone in my area, you get you 500 easy. But each market is different. At least we are going into spring. Hell you could try selling with the issue disclosed to a gearhead that loves to work on engines and would not mind the project.

Good luck on whatever you choose.

97Snyder 04-08-2013 01:28 AM

5 Attachment(s)
This is the jeep

InvisiblePants 04-08-2013 10:35 AM

She's a beauty. I wish my PO would have left mine that green. He painted it black, and it looks good, but i love the metallic green.

97Snyder 04-08-2013 07:15 PM

I agree it is a great color for the vehicle.

bardb 04-09-2013 09:48 AM

If you're happy with the Jeep, then I would look into rebuilding whatever is broken now. A top end rebuild is obviously quicker than a complete engine pull and rebuild. If time is critical you can swap with a rebuilt one, but personally I would rather rent a car and take more time to rebuild the originals if possible. The link below may have some useful rebuild info.

http://www.wranglerforum.com/f5/4-0-...ce-119597.html


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