Dyeing Cylinder

[sd2649]

Long story, but here goes. I bought this truck about 3 months ago. It is an 89 f250 with a 7.3 idi. the 7.3 is from another truck as it is dated for 1991. I have no idea how many miles, but the engine starts right upon the first turn and has been very dependable. The problem is that on startup, one cylinder has always taken about 20 seconds of idling before it would start to fire. It will start earlier if I rev. This would less of an issue if it didn't burn oil really bad, about 5 quarts for 300 miles. Looking at the blowby, i noticed that there was a VERY noticeable puff every revolution, so I figured it was that same cylinder. Also, before that cylinder starts to fire, the engine is nice and quiet, no clicks or anything, just a little shake for the dead cylinder, however once that cylinder starts to fire, a loud clack clack clack can be heard. I thought it may have been a stuck open/closed/screwed up injector, so I changed them all out with no help. I then diverted the CCV (Crank Case Vent) to a long hose, copper pipe and then strainer filled with copper scrubbing pads. the hose then went down and dumped below the cab. I successfully collected alot of oil, but it still leaves a nice coat of oil on the back of my cab due to the large amount of smoke still coming out. I am certain that this is where all of my oil is going, due to blowby, not valve guides.

I decided today to get my brother to listen for the clack as I bled each cylinder seperately and we found the issue cylinder, it is the drivers side closest to the windshield. I took out the injector, diverted the open fuel lines and started it up to see if it was also causing the blowby. Sure enough, drastically less blowby and no puffing like before. I am now letting the cylinder soak in a mixture of diesel and carb cleaner, hoping I have a stuck cylinder ring.

OK, so......... think this will work??? the cylinder would come and go as I was driving, sometimes no smoke from exhaust, usually very little, but sometimes when I am at highway speeds, white smoke will come out during decelleration. But if I got on the throttle a while, it would go away completely!!!! are my cylinder rings sticking and then coming unstuck?? the soak I put in is not running out, it is staying, so it's not a hole in the piston, maybe a crack?? cracked cylinder rings??

Any feedback or good ideas would be VERY much appreciated!!

 

[Black Horse]

Maybe at one time the previous owner had a glow plug tip break off and do some piston damage.

 

[sd2649]

new development......


I went to turn over the engine to get the "soak" out and it was all gone this time. nothing at all in there, so I'm guessing there is some scarring in the cylinder wall or maybe just a hole.

Funny thing is this, i went ahead and started it again to see if the blowby was really gone and it was, hardly anything coming from the filler neck or road draft tube, but as it ran, smoke was being shot out by the dead cylinder through the injector hole, alot of smoke, just about as much as was missing from the rest.


So....... is the piston without the injector in able to suck in the crank case smoke and pump it out of the injector hole????? is this smoke from the cylinder due to oil getting in through the cylinder rings and then mistified(????) by the compression, or is this in fact the crank case smoke coming in through something else????? if so, there should be suction on the filler neck?? if so I could check that.

I am really stumped and need some major help on this diagnosis. Please, and helpful hints.


A dropped glowplug WOULD indicate a hole in the piston, but why the change in location of the smoke???

 

[sd2649]

OK, I checked and the crankcase still has the same pressure as before!!! so, the smoke coming out of the "dead" cylinder injector hole is being created INSIDE that cylinder.

So, what does that mean??????

is there a possibility that the oil from the crankcase is getting in somehow and then being compressed (mistified????)

HELP! HELP! PLEASE!!!

 

[zpd307]

first off, i am no expert. but i am thinking there is a hole in the piston. i bet if you do a compression test on the cylinder. there will be practically nothing. i bet the blow by from the motor is going through the hole in the piston and then going out the injector hole. i wouldnt think the scoring in the cylinders would be so bad as to let blow by through. on another thought. would the blow by be sucked into the cylinder from the cdr.

 

[Agnem]

I would do the compression test as mentioned, but I would also pull the valve cover and do a visual inspection with it running. We just did this last weekend. Not too messy. Click Here.

 

[icanfixall]

I dought you have a hole in the piston. These piston tops are 560 to 580 thousands thick. You probably have a ring problem. Sorry but its time to pull the motor and dig into it but... Do as Mel suggested first... Pull the valve cover and have a look see...

 

[Devilish]

Any number of things could be causing your issue. Worn, broken rings or piston damage would be things to look for. I'm also wondering if the engine may have been overheated before. The engine tag on the valve cover will show void all over it if the engine got too hot.
Do a compression test on the cylinder then put a little oil in the cylinder and test again.
Low compression at first then higher compression after second test means worn rings. Low then low again means much more serious.
For that matter you should compression test all cylinders to get a better understanding of the actual condition of your engine.

 

[sd2649]

Ok, so where is a good place to get a compression tester?

I do not have the cdr anymore, it's bypassed to a road draft tube. That tune still had the same pressure with the injector out, so no auction from the cylinder. I now am thinking I have a busted valve that is letting exhaust/intake gas into the cylinder.

I put it back together today and drove it to work(63 miles) and the blowby was persistent, but the cylinder fired from the beginning and the engine ran MUCH smoother. So I am possibly thinking that I had stick rings and a bad valve with horrible valve guides contributing to the crankcase pressurization..... Maybe?????

The motor has not been overheated and the other cylindes produce very little blowby on their own. Even the bad cylinder has enough compression to fire at idle without any trouble. It was 55 degrees this morning and fired right up. I am hoping over the long run, I will see a little less oil consumption now, but the ticking noise is still there. I will pull the valve cover tonight and let yall know what I see. Thanks for the help again!!!

 

[Devilish]

got harbor freight in your area?
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=93644
You could try adding Diesel Kleen or other additives to your fuel and see if that will un-stick your rings. Many in here have their special chems for doing that and will gladly chime in with the options

 

[sd2649]

I just watched the video of the headgaskets off. what should I be looking for as I do this??????

 

[Diesel JD]

I think its possible that Gary is right and you had some stuck rings or hes wrong and you have a big old hole in that piston and it will basically come out in bits when you pull the heads. You're looking for any holes, cracks or big time obvious problems with the pistons. You'll see the bore have a ridge at the top, some of that is normal though not desirable. You also may encounter some dings and dents on top of the pistons from glow plug tips and possible valve contact. If you don't have any more significant engine damage you might just think about running it as is.

 

[sd2649]

I would be running it as is if it weren't for the horrible oil consumption.
I was asking what to look for with the valve covers off, not the heads.

I ordered a compression test kit yesterday and will post my results whenever it comes in.

Until then, I huesax I'm stick burning oil like crazy.

 

[Agnem]

I just watched the video of the headgaskets off. what should I be looking for as I do this??????

When you pull the valve cover give every part a good wiggle. Shouldn't be a lot of motion in there. When you start it, see if one set of valves moves different then the rest.

 

[sd2649]

I still haven't received my compression tester, but I took off the valve cover today and here's what I've found.

If this is right "Cylinder numbers are assigned 1,3,5,7 on the left(passenger) bank from front of truck to back, and 2,4,6,8 on the driver's side, front to back. Firing order is 1,2,7,3,4,5,6,8." And hopefully it is...

Then I took off the drivers side bank valve cover (cylinders 2,4,6,8) and noticed the following:

Remember that cylinder 8 was the one that caused the ticking noise, I saw a small puff of smoke coming from the #2 intake hole and a more constant / larger puff coming from the #8 cylinder exhaust hole (as suspected). What has me worried is that there was FAR more smoke coming from the push rod holes (crankcase smoke I would assume). the smoke was a different color than the exhaust gas and wasn't as dense, in any one hole, but overall it was more than the valves. I will note that the puff was still noticeable from the oil fill tube with the valve cover off, so this puff must be caused by blowby from one of the cylinders... I am still guessing #8.

Does this sound right??? any chance the blowby puff is from a different cylinder after all this research?????