Somethings totally wrong with my 98 lude. CEL is on, heavy bogging, heavy misfiring, and after a leak down test it was found that Cylinder 1-75%Leakage, Cylinder 2-15% Leakage, Cylinder 3-30% Leakage, and Cylinder 4-10%Leakage. Is this a blown head gasket, piston rings, valves??need help.

 

The leak down should be able to tell you what's wrong.
Listen to the "hiss".

If the head gasket is blown, you should see bubbles in your coolant system while performing the leak down test. Other signs include oil and coolant mixing (coolant in the oil, oil in the coolant system).

If your piston rings are worn to the point of 75% leak down, then you should feel a decent amount of air out of your dip stick or plug holes. Other signs include excessive blowby when the engine is in operation, maybe your plug wires pop out or distick pops out. Excessive oil in your catch can if you have a catch can.

If your valves are bent, then you should feel/hear air leaking through the valves that are bent by during TDC (all valves closed). Causes of bent valves include but not limited to overreving or timing belt snapped.

I want to say that you probably have bent valves, but with a leakdown test you should be able to pinpoint the problem.

 

i had bent valves that were fixed about 3 months ago...but this time its different no ticking....but it doesnt idle..but my car shakes and you can hear it sputtering. Radiator water is darker and has some ashey form in there. The oil seems fine though. CEL throughing misfire codes. Can it be something else. I changed some of the ignition system. Plugs, wires, cap, rotor all OEM. The mechanic at the local dyno shop said it might be the head gasket so im having them take it off. But can it be anything else possibly??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k_lude &raquo;</TD></TR><TR><TD CLASS="quote"> Radiator water is darker and has some ashey form in there.</TD></TR></TABLE>

That sounds like you have a blown headgasket.

If you have no reason to suspect bent valves, then it's probably not that. Since you just fixed that 3 months ago. However, if you accidentally over-revved sometime during that 3 months, I would bring the head to a machine shop to make sure your valves are straight.

 

just got the report from the mechanic....my head was sent to the machine shop and had carb developed on 3 valves...is this the meaning of a bent valve possibly. Ive aranged to change all of the valves.. but what can cause carb developing on my valves and some were on the pistons?? I heard it was gas but i pump 91 octane......need help?

 

its caused by a combination of alot of things. Heat, gas, and also when your guide seals go out it causes he automizer effect.

 

so im wondering...if i get new valves would it fix everything?

 

HELP...

 

What did your machine shop say to do?

 

does your motor need 91 octane? if not dont waste your money.

 

well they retested the head today..all intake valves bent..then when i got to the shop not the machine shop but the one i took it to they called and the exhaust valves were all bent, they've only taken two intake valves and they were good..i want all of them changed though...shop costs for labor $600-$650 with all gaskets...machine shop???all i know is that to pressure test is $50 and if they do all the valves it costs $850 for everything...but there not sure any more...how much do u think it'll cost???is it time for a new head or is it still good?