[thechrisgibson]

*New readings for compression test. This time the engine cranked once and the result was recorded. Then the gauge was NOT reset and then the engine was cranked again and those were recorded. This was done 4 times on each cylinder and her are the results. We then cranked it about 5 or 6 times and those were lower than before (below).

Cyl-1 1 Crank @ 99.25 psi
2 Crank @ 129.25 psi
5 or 6 cranks @ 125 psi
Cyl-2 1 Crank @ 96.25 psi
2 Crank @ 121.25 psi
5 or 6 cranks @ 135 psi
Cyl-3 1 Crank @ 92.5 psi
2 Crank @ 121.25 psi
5 or 6 cranks @ 135 psi
Cyl-4 1 Crank @ 97.5 psi
2 Crank @ 125 psi
5 or 6 cranks @ 145 psi

Hope this helps*

Ok for those of you who are new to the story, my 87 wrangler with a 4 cyl jumped into 3rd gear while I was pulling out of my driveway while I was flat towing it. It went 90 miles on the highway before I noticed and yes I feel like a total ****** for letting this happen. Anyways it started putting out whiteish/blueish smoke and would turn somewhat grey when I put the throttle down. It also started leaking coolant which was coming from the water pump and that problem has been fixed. So the smoking remains and I was told by several people to do a compression test and here are the results. Now when I say Cyl-1 I am talking about the cylinder closest to the front and the numbers get larger as we progress backwards.

Cyl-1 is 151 psi
Cyl-2 is 155 psi
Cyl-3 is 152 psi
Cyl-4 is 156 psi

Here are some pictures of the spark plugs which are labeled with the cylinder they came from (i.e. 1, 2, 3, or 4). http://public.webbox.com/680000/

Hope this is enough info to help you guys get a better idea to what could be wrong. Thanks again for all of the help and if there is any other info that would be helpful please PM or email me and let me know.

[Questor]

Those compression numbers are pretty decent, I wouldn't worry about anything until down to around 125 PSI.

Note, not saying you did this, but I've seen it so many times that it's worth mentioning, compression readings should always be taken with one crank of the engine (assuming proper lubrication), not "built up" by repeated cranking until you get a nice high reading. One or two cranks, reset the gauge, retest, do this four times on each cyl and avg the results is how I usually go about it...

A likely candidate for your burning is the valve stem seals - how many miles on your rig? Have the heads ever been done? How much smoke are you dumping exactly, and do you appear to have any water mixed with your crankcase oil?

[traildust]

Agree if compression test was done right I would say they look ok. Build up on plugs I would also think perhaps valve seals or valve guides. Not sure what to say about white smoke and the draker smoke. Sorry

[thechrisgibson]

*New readings for compression test. This time the engine cranked once and the result was recorded. Then the gauge was NOT reset and then the engine was cranked again and those were recorded. This was done 4 times on each cylinder and her are the results. We then cranked it about 5 or 6 times and those were lower than before (below).

Cyl-1 1 Crank @ 99.25 psi
2 Crank @ 129.25 psi
5 or 6 cranks @ 125 psi
Cyl-2 1 Crank @ 96.25 psi
2 Crank @ 121.25 psi
5 or 6 cranks @ 135 psi
Cyl-3 1 Crank @ 92.5 psi
2 Crank @ 121.25 psi
5 or 6 cranks @ 135 psi
Cyl-4 1 Crank @ 97.5 psi
2 Crank @ 125 psi
5 or 6 cranks @ 145 psi

Hope this helps*

Ok for those of you who are new to the story, my 87 wrangler with a 4 cyl jumped into 3rd gear while I was pulling out of my driveway while I was flat towing it. It went 90 miles on the highway before I noticed and yes I feel like a total ****** for letting this happen. Anyways it started putting out whiteish/blueish smoke and would turn somewhat grey when I put the throttle down. It also started leaking coolant which was coming from the water pump and that problem has been fixed. So the smoking remains and I was told by several people to do a compression test and here are the results. Now when I say Cyl-1 I am talking about the cylinder closest to the front and the numbers get larger as we progress backwards.

Cyl-1 is 151 psi
Cyl-2 is 155 psi
Cyl-3 is 152 psi
Cyl-4 is 156 psi

Here are some pictures of the spark plugs which are labeled with the cylinder they came from (i.e. 1, 2, 3, or 4). http://public.webbox.com/680000/

Hope this is enough info to help you guys get a better idea to what could be wrong. Thanks again for all of the help and if there is any other info that would be helpful please PM or email me and let me know.

[ErikJordan]

those numbers sound pretty good from what i can remember is required.
when i did my compression test on the 4.0, i had one that was like 50 pounds low.
yours may all be slghtly low, but are relatively close to one another.
i am by no means an engine expert, so... lets wait for more responses.

[Questor]

Looks like those numbers are a little low, you might have trashed your rings when towing if there wasn't enough (at temp) oil making it up there to lubricate them properly.

Here's the next step - to determine WHY you're getting low readings, dump about a tablespoon of 30 weight or better oil (some guys use gear lube) through each spark plug hole, crank enough times to get the oil distributed over the piston and rings, and then re-take the readings - if they are still low, good(ish) news, it's your valves that are leaking, so you only need head work, if they go up considerably, your rings are the culprit and you'll need a re-ring, or potentially more if the damage was significant enough to damage the cylinders...

Let us know how this goes, and maybe the results will show some good options.

[ryanfritz]

good thing is that all are similar, not only the compression ratios, but also the plugs, from what i know (and have been told) that is if all the plugs look the same, that most likely you do not have a head gasket problem,

bad news: this is all i got for ya.

[BudmanV6]

Not to hijack this post, but Nailer, what was the outcome after your compression check? Did you just leave it? I checked the compression in my 4.0L and it ranged from 155 at one of the rear cylinders to 90psi in the two front cylinders. Plus, I lost about 2 quarts of oil in the last like 2700 miles that I drove. I was really short when I changed the oil recently.

[ErikJordan]

i bought a new motor on ebay, and put it in there

[sentinal02]

Originally Posted by Questor

Looks like those numbers are a little low, you might have trashed your rings when towing if there wasn't enough (at temp) oil making it up there to lubricate them properly.

Here's the next step - to determine WHY you're getting low readings, dump about a tablespoon of 30 weight or better oil (some guys use gear lube) through each spark plug hole, crank enough times to get the oil distributed over the piston and rings, and then re-take the readings - if they are still low, good(ish) news, it's your valves that are leaking, so you only need head work, if they go up considerably, your rings are the culprit and you'll need a re-ring, or potentially more if the damage was significant enough to damage the cylinders...

Let us know how this goes, and maybe the results will show some good options.

yup, definitely do the oil next. like Questor said it will tell you where you're losing pressure from. whitish smoke though sounds like you blew the head gasket. sounds like a good reason to get the cylinders overbored and squeeze some more power out of that 4 cyl

[thechrisgibson]

Ok today I was going to do the oil test on my jeep. So I put a tblspn in each cylinder and cranked it and the numbers did go up a bit. So I started it up and there was no white smoke. There was blue smoke but that cleared up in about 5 minutes. So now my jeep is running like it used to. No smoke at all. I don't know if the rings are worn but judging by the numbers on the gauge getting higher when I added oil they should be right? But then if the rings are worn shouldn't it be smoking? Well I just wanted to let all of you know that it apparently is fixed (or at least runs and drives like it is fixed). Thank you guys for all of your help.

[ErikJordan]

Threads Merged

[Questor]

Glad to hear that your jeep is running better!! The blue smoke you saw after doing the test is obviously burn off from the oil used for the test. If the numbers got better, your rings weren't sealing as well as they should have been, but as is common in older, high mileage engines, it's likely a combination of rings and valve seals.

I don't want to bring you down at all, but you're improved situation may be a temporary result of the oil you dumped on top of the pistons sealing the top ring better and might stop after so many miles. However, it also could indicate that your oil rings are having a hard time lubricating the cylinder walls and compression rings properly and, on a positive note, this oil may have helped free up any stuck oil or sealing rings that could have been causing smoking.

Not that I recommend this, but I've seen new life breathed into an old tired V8 which was smoking and whose previous owner had never changed the oil (don't ask) by dumping about 1/2 a cup of seafoam in each cylinder and manually moving the crank to and fro for a couple minutes, rest for a couple minutes, then agitate again, etc... after this, the engine was cranked with the starter a few times (no SPARK!) to really get the seafoam down into the rings, and then let sit for about five minutes...

It was explained that this was effectively 'cleaning' all of the solidified old oil out of the compression and oil rings, and allowing them to move freely again, and hopefully do their job a little better.

After this rest period the engine was started up, and boy did it dump out a ton of smoke and carbon, but finally settled down, and after flushing the oil out, and filling it with fresh lube, the engine ran like a champ and hardly used any oil... (yes the oil was changed to fresh before this process began as well)... I guess this is an old trick for abused engines...solvent in the cylinders to free up the rings and (hopefully) allow for better compression. If your problems come back, this might be something to try before serious work or replacing your engine.

Hopefully though, you are good to go for a while!


NAILER,

What do you mean by 'merged' exactly? I still see both posts in the forum and search, and I don't see my response to the original thread in here...no offense at all, just wondering.

[bcshepard]

Just curious.. what happened to ears and a tach? Couldnt tell the motor was running a bit fast?

[gbeltran]

He was towing the Jeep and it was inadvertantly in gear.