The car has been running very poorly. I replaced plugs wires distributor cap,rotor, checked engine and ignition timing, both within specs, tested compression and found cylinders 1&2 had 35psi. cylinders 3&4 about 150psi. opened valve cover nothing looked to bad. What to check from here please...
Burned valve is likely the culprit.... or bad rings.... hook air up to that cyclinder one at a time.... and listen where the air is escaping... be aware that the motor will rotate till the piston is at the bottom of it's rotation. if it's a burned valve you will have to remove the head and replace it but somewhat easier job then replacing the rings. darn almost forgot.... it can also be a blown head gasket.... same procedure but you might need a brush and some soap water to test for an air leak at the side of the head. when you are done spray some wd 40 on it to get the water off so the spark plugs do not arc.
Robert
If the cylinders are side by side.. it is most likely a blown head gasket tho it usually displays other issues but not always. if it was a gradual loss in performance it could very well be burned valves. is that motor made by volkswagon by chance. yes i'm away the brand is mitsubishi but companys sometimes by major components from other companies. I would be interested in what miles (kilometres) the motor has on it. also check your motor oil ... what colour is it. rings generally if the fail are would usually show low compression on all the cyclinders.
oh and has that motor overheated lately ?
Robert
Yes.... you can used the compression tool... but i'll tell you a quick way to make one... take an old spark plug that will fit that motor... knock the ceramic core out of it and use a hose clamp to attach the air to it. finger tighten it into the spark plug hole and add air... and listen watch for escaping air. that should narrow it down.
Robert
although this might be longer to do... you need to confirm it is burnt valves..... i'm not sure of the firing order but when you add air the piston should have gone to bottom dead center. if i'm remembering right no valves should be open. as much as it's possible that you do indeed have two burned exhaust valves. perhaps dissasmble the motor to the point where you are going to change the head. you are going to need a head gasket at the very least.... when you remove the old head gasket examine it... if it was the actual cause of the leak you will know by looking at it. I guess the only thing i can say about the price is to call around and look online to compare prices.
Robert
i replaced head still no compression r fire at plugs
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thank you very much, which of these possibilities (if any) would be more likely to affect more than one cylinder at a time (the two cylinders affected are right next to each other. 4,3,(2),(1), this being the cylinder layout (#)= affected cylinders.) the firing order is 1-3-4-2 . hope this makes sense. thanks again
the performance issues pretty much happened instantly or within a very short time. the motor has 170,000 miles on it but prior to this had been running quite well, (never stalled, always had consistent power/acceleration. Not sure if the motor or components were made by other companies. I know it is the original factory motor 4G37 sohc and yes last time I drove it , it overheated within a very short distance less than 2 miles. I will be testing some more today now that Im done with work. by hook up air to the cylinder does that mean like blowing compressed air into the spark plug ports one at a time? thats what you mean right?
- I Really Apreciate Your Help.Thanks-
So I hooked up air to cylinder 1 and heard air escaping from the exhaust pipe.so I opened the exhaust pipe just behind the exhaust manifold and felt the air moving past. I did the same test on cylinder 2 and had the same results. So if the air is going out the exhaust then I must have a problem with my valves right. I found re-manufactured heads online for $300 and $30 shipping. Does that sound like a good deal, cause I'm not sure I'm can do the valves myself. Or if it is worth trying.
Thanks for Input. (very helpful/knowledgeable)
So I tested it with copressed air, and then moved the crank and tested. it turned out to be just thehead gasket, between the #1and #2 cylinders was bad. Well thanks again for your advice
2003 x5 4.6is ran fine one day. the next day would not crank. had it tested and found that it had very low compression in all cylinders. What could have caused this?
found out there no compresion in the #4cylinder on left hand side. how hard is it going to be for me to fix. i know very little about this stuff
do not have any compression in the #4 cylinder . did a compression on it. i know very little about doing this of thing
Saturn sl 1 does this mean the engine is gone
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