QuestionThank you for the quick response. As far as the oil or the coolant, there's no discoloration.
The truck has been running 'fine' yet a couple tell tale signs. yes the, the check engine light had popped up a couple times. After checking the manual, it said to check things like the gas cap to be fully tightened...."
- I did find out that my wife had been putting 87 oct in the tank when the manuacturer says to use 91....might be associated?
- Anyhow, i just had the tranny flushed, and the Lincoln foreman asked if I'd hear the engine misfiring. Specifically mentioned #8. Not being trained, I didnt hear anything and the problem surfaced while having it smogged...
So, runs fine, not sure what the non trained smog guy knows for real, but having the lincoln mechanic mention he heard something the day before leads me to think there is "something wrong"
Any help with the above input?
Thanks so much.
chris
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Followup To
Question -
Hello,
Smog guy telling me no compression in the #8 cylinder on my 03 Navigator. What could cause this so I can be a little proactive with a mechanic I'll be speaking to tomorrow? Is this usually a blown gasket or valve, and how costly is this problem to fix,,,usually?
Thank you!
Answer -
Hi Chris,
Assuming that the smog guy is right. (I don't put much stock in the not so overly train smog technician though). The cause could be a blown head gasket so lets look for a couple of other things. Pull your engine oil dipstick and look for discoloration. White film or brown bubbles. Second, look at the coolent. Look to see if you have the same thing like brown floating on top or a white film on the cap. Did you have a check engine light on and if so the smog guy should have been able to tell you the codes. Lastly, does the truck run like crap? There is generally no such thing as no compression unless the piston is broken or worse, but you would have heard that for sure! There could be a reading of LOW compression if you had a bad gasket or burnt valve that wasn't seating. I tend to believe, knowing Navi's like I do and the reliablity of the 5.4, that the smog guy has faulty equiptment or is just guessing. I can't see how smog testing equiptment can distinguish what is happening to what cylinder other than firing. I know some equiptment will read your data stream and can give you some type of idea if the engine is not running well. But again, the computer would have tripped a code giving you insight to what is happeneing, if anything. If you do have a broken cylinder, then I suggest a short block. Very expensive repair. $3000 plus. A head gasket job should be under a thousand as well as a valve job.
AnswerWell, that's to bad, because the 87 octaine probably burnt a hole in the top of the cylinder. This will cause a no compression reading for sure. I was trying to find more info on the web about this, but there isn't much out there. If she has been using the cheap gas for a long time then there is likely damage to the other cylinders as well. You might look around for a short block or a complete engine on the web to save a little. Good luck, Chris. If your in the Vegas area, I have a guy that will do this reasonable.
