Three bad cylinders!

[Osmosis]

I recenlty purchased a 93 typhoon. It was supposed to have had a rebuilt engine and tranny with under 2K miles on it. I noticed I had excessive oil consumption, to the point where to change my oil, all I would have had to do is change the filter and keep adding oil. The only changes I did to the stock truck was I put the ultimate chip in with 3 bar map, 255lph pump, AFPR @ 45psi, and a 255lph fuel pump.

I rarely boost it past 12psi, I"m easy on it for now. I boosted it up to 18-20 a few times last week and it seemed to lack power or "umph" over 14psi. I got into the boost the other day and I had a considerable loss in power with smoking coming out the exhaust. I thought...that aint right. I called in sick the other day and worked on my ty. Here's what I found.

Two cylinders on the passengers side and one on the drivers side had fouled plugs. I did a compression test the 3 suspect cylinders had aprox 25% decreased pressure than the other cylinders. I squirted 10cc's of oil into the suspected cylinders and the compression increased almost 15%. I suspect the rings are not seating or have never been replaced. they guy I bought it from had receipts......."rebuilt engine" was not done right or not at all:rant:

The ty had good idle quality, just smokes and lacks power in boost above 14psi, fouls plugs quick and burns a ton of oil!

Any thoughts? I am sure I am gonna have to pull the engine:tdown: I am NOT happy.

 

[Luke]

Re: Three bad cylinders!

was a comp test done prior to purchase? it doesnt sound good. should pressurize the cyl's and see where it is going.

 

[Raist103]

Re: Three bad cylinders!

same thing happened to me but i found the block was a 98 rods and pistons were mismatched and cam was wiped all with 10k miles on the "rebuild" it happens just got to deal with it. 2200 later i had a new motor and it ran great. our fault for not checking things better before we buy.

 

[Don W.]

Re: Three bad cylinders!

How was the oil consumption before you "boosted it up to 18-20 a few times last week?"

 

[turbodig]

Re: Three bad cylinders!

If they rebuilt it with stock pistons, you cracked the ring lands, most likely.

This is the danger in not knowing if something is knocking. A perfectly good motor can be trash in a couple of seconds. It's entirely possible (probable) that the motor was good, and built properly.

18-20 psi on pump gas is an almost certain death, if it wasn't dead already. Even stock boost with a bad tune will kill them in short order.

Even a 100% stock system can kill a motor if the wrong sequence of events occurs.

 

[Osmosis]

Re: Three bad cylinders!

I've built a ton of engines as I used to work for a guy named Art Morrison while i was in highschool. I suspect the rings are toast as it runs fine at idle up to 10psi boost. The truck idles great, 20 inches of vacume once I put new plugs in it. purrs like a kitten. Drives normal too. It does seem a bit sluggish and once I get into the boost over 14psi, it falls flat and smokes really bad. It became progressively worse over a matter of a few weeks, I noticed once I got into boost over 14psi. Then the other day, I noticed the smoke!

I replaced the plugs and then I pulled the plugs after driving it normal and the 3 bad plugs looked fine...not too bad. Then I did a boost run and the 3 cylinders fouled the plugs again. I would bet the problem lies in the rings somewhere. I'm not gonna be able to have a difinitive answer until I get a chance to tear into it until a month or two, I've got a few hazmat classes for work I have to deal with until Dec 20th..ugh! Once the holidays are over, I'm gonna tear into it, man, NOT HAPPY! I did tune my ty with the ultimate chip till I had no knock @ 18.5psi when I first got the truck and it ran well. However, I have been suspicious of the truck since I purchased it as the truck consumed oil rather quickly! I rarely have boosted the truck over 10psi as I'm just getting to know it. I probally took it up to 18ish psi about 10 times max, mostly tuning it. And I always...ALWAYS use 97 octane from a local gas station that sells premium fuel.



I'll keep ya informed, maybe pic's to come.

And how are seal-pro gapless rings on our trucks?

 

[nfmRc8q]

Re: Three bad cylinders!

I've built a ton of engines as I used to work for a guy named Art Morrison while i was in highschool. I suspect the rings are toast as it runs fine at idle up to 10psi boost. The truck idles great, 20 inches of vacume once I put new plugs in it. purrs like a kitten. Drives normal too. It does seem a bit sluggish and once I get into the boost over 14psi, it falls flat and smokes really bad. It became progressively worse over a matter of a few weeks, I noticed once I got into boost over 14psi. Then the other day, I noticed the smoke!

I replaced the plugs and then I pulled the plugs after driving it normal and the 3 bad plugs looked fine...not too bad. Then I did a boost run and the 3 cylinders fouled the plugs again. I would bet the problem lies in the rings somewhere. I'm not gonna be able to have a difinitive answer until I get a chance to tear into it until a month or two, I've got a few hazmat classes for work I have to deal with until Dec 20th..ugh! Once the holidays are over, I'm gonna tear into it, man, NOT HAPPY! I did tune my ty with the ultimate chip till I had no knock @ 18.5psi when I first got the truck and it ran well. However, I have been suspicious of the truck since I purchased it as the truck consumed oil rather quickly! I rarely have boosted the truck over 10psi as I'm just getting to know it. I probally took it up to 18ish psi about 10 times max, mostly tuning it. And I always...ALWAYS use 97 octane from a local gas station that sells premium fuel.



I'll keep ya informed, maybe pic's to come.

And how are seal-pro gapless rings on our trucks?

Yeah, I think you toasted the rings too.. if adding oil to your compression test shows you 15% more compression you just found your problem. Maybe you should do a cylinder leak test just to be sure, it could be a scratched cylinder too. I don't know about gapless rings on OUR trucks.. but in every other engines i worked on (for a race engine application) gapless rings are the best bet. my 2cents.

 

[Osmosis]

Re: Three bad cylinders!

Yea, I need to do a leak down test, however, i dont 'have one. Either way, I have to tear into the engine, so it's a no brainer at this ponit. I do have a friend who has one and I plan on using it once I get done with this booring class I am required to take for work:squint: Either way, I'm tearing into the engine. I'm really tight on funds and I may just try either work some OT and save up to do the engine right! Since the guy I purhcased my typhoon from said the engine and tranny have been rebuilt, I'm gonna tear into the tranny too! I'm gonna pull it apart and check tolarances and what not. I rebuilt my 700r4 for my Z a few years back and had considred saving that tranny for my ty, but I think we have the 480le instead. Either way, i can rebuild the tranny myself if need be, best thing out of this whole nightmere is I will be sure of what is in the truck. What a PITA!:rant: