86 Monte Carlo knocking

[skatepirate77]

I have an 86 Monte Carlo with a 305 and 2004r. After driving for about 20 mins or more it starts to lose power on take offs and knocking. It kinda sounds like a diesel truck when it does it. Oil pressure is about 30 psi. When i go to stop it almost kills the car and shutters to a stop. When turning corners and hitting the gas it knocks. But with i let it cool off it goes away until the car warms up again. Anyone know what is causing this or has had this happen and knows a fix for it.
thanks matt

 

[zuma83]

maybe bad plugs

 

[skatepirate77]

I just put them in last month you think they could fault they quick. I will pull and check them. Thanks

So I pulled plugs looks fine also checked wires they look fine. I read that the egr could cause horrible knocking like a bad rod knock if the valve doesn't open like it is supposed to so i will check it and clean it while it is off to see if that helps. Is it weird that i get knocking only when engine is warm and i take off from a full stop?

 

[jmt455]

A plugged exhaust system could make it act like this. Check for a plugged catalytic converter.

I'd also check the TCC lock-up solenoid. If it is kaput, the torque converter won't unlock when it's supposed to. The car will practically stall when you come to a stop.
Try driving it in D instead of OD - if that cures it, replace the solenoid.

 

[megaladon6]

can you post pics of the plugs?
a plugged cat is similar, but usually sputters instead of knocking. it sounds like you're going lean. one car that had very similar symptoms to yours that drove me nuts, had a partially plugged "sock" in the fuel tank. an easy check is to detach the fuel line and blow compressed air down the line to the tank. this will blow out (and destroy) the sock. if everything is good after that, pull the gas tank and replace the sock/sending unit. you may also want to replace the fuel filter. also, look carefully at the plugs, if they are white, with no brown at all, possibly blistered, then you are running lean.

 

[zuma83]

have you played with the dist.

 

[skatepirate77]

I am going to drive it around in D tonight to check. I will also try the compressed air trick tomorrow when i get time. Does anyone know if overheating with cause it because when messing around with it today I realized the top radiator hose does not have any pressure at all. I just replaced the water pump, t-stat, hoses, and radiator last week. I am wondering if the fan clutch is gone and causing it to overheat. I can't trust my gauge cause it is only a the first dot which i am assuming is 200 F. I am also going to check the timing tomorrow to make sure it hasn't moved. I checked my dwell today and it is at 33 on 6cyl cycle. I think that should be ok since it only needs to be 30. Thanks for all the input. I can always count on you guys here to help me.

 

[megaladon6]

if the fan clutch is gone, it should only overheat when stopped or operating at low speed. at higher speeds there is enough natural airflow to cool things down.
if the top hose has no pressure, you shouldn't be overheating, unless there's another issue. check the oil and cap for white "yogurt" also check the coolant for oil. you may want to keep an IR thermometer to check the head, radiator, and hose temps when driving.

 

[skatepirate77]

Yeah is only knocking when i drive for about 20 mins. Then when i go to stop it shakes and shutters like it wants to die. When I go to take off it is serious knocking then goes away at about 30 mph. I only do around town driving. So tomorrow I will check timing, check vacuum, check radiator pressure, I am thinking about pulling new t-sat and boiling it to see if it opens, I am always go to drive around in drive only to see if it is the lock up. Is there anything else I should check for tomorrow. Something keeps making me want to think it is an overheating problem cause when my lights are on and i shut the car off with them on the temp gauge goes all the right and stays there even when i turn off the lights. Thanks again for everyone taking the time to help me on this. I know it is hard to tell what it is for you guys without really hearing it or being in the car.

 

[skatepirate77]

Well it is all fixed up and running like a champ. Turns out the t-sat wasn't opening at cause it to overheat and knock. I also fixed temp gauge it was a lose wire in the dash. O the good times working on the monte. Just thought i would update i got it fixed. Thanks again to everyone that helped out.