CyprusMustang

Ok so I did a c4 to AOD swap. Car has been sitting for 3 years. I've also changed radiator, few hoses and couple other things.

Now I start the engine for first time after three years and after warming up for about 15-20 min and engine reaches it's running temp I get this knocking noise and jerking of the coolant hoses.

So I let cool down a bit and out of curiosity I do a compression test. All cyl are running around 160 give or take. All plugs show unburnt fuel ( my engine running rich) and no water in oil.

Now I put everything back and let cool down completely. I fill radiator to about an inch of visibility and start engine with no cap on. After 15-20 min when car reaches running temp, the knocking begins and the coolant begins to overflow out of the radiator.

Does this mean my head gaskets need replacing?

Also, on another note my engine is running rich ( prob I always had) and I get water out my tailpipes even after 15-20 min of warming up.

Any thoughts???

LimeGoldCoupe

I have/had the same issue, car sat for a long time, filled it with coolant, started her up and let her run with the heater on high, after shutting it off I get the same noise and jerking of heater hoses.... Not sure why but my 289 has just been rebuilt so it's "probably" not the head gasket. After starting her back up thinking there was trapped air in the system I leave the cap off and get the same explosion/geyser of coolant all over the place.

Could this be due to a clogged radiator? I haven't replaced mine.

I still have a sneaking suspicion that it's due to trapped air but I'm weary of opening the cap and starting it up again, cleaning coolant isn't fun.

CyprusMustang

Please explain the noise. The noise I hear is around the passenger side and only starts when car temp reaches 150-160 about 15 min after startup. It's like a pinging/clunking noise. Almost sounds like knocking of a valve but I see hoses shaking and a clicking in the heater box.

What I'm gonna do now is bypass the heater box by joining the two hoses above the engine as well as check for a misfire ( could be a combination of noises).
It's definitely not my radiator as I just changed it along with all the other things I did.

barnett468

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you have a blocked water passage or you lower heater hose is compressing . . if it is still round when it does this you have a plugged water port . . if the head gasket was bad it would be steaming out the tail pipe. . . remove the water pump and see if the impeller is rusted away or the ports on the timing cover are plugged . . if all is ok, yank the heads.

69mach1377

Yeah, I had a car once with a leaky head gasket and it steamed out the rear so bad it looked like a james bond camoflouge trick...

fastbackford351

Water dripping out of the tail pipes isn't bad. I had a Pontiac 400 that you could almost fill a glass with the water that consistently poured out of the exhaust.

I can't remember the explanation I heard as to "why" years ago but I'm sure some egg head around here can drop that knowledge on us.

MonsterBilly

Sounds like air. You can try to remove the t Stat and let it run flowing freely for a while. See if that gets things moveing. Then try to flush the system

CyprusMustang

Ok this is driving me nuts.

I believe I have a bad misfire due to the carbon build up on my plugs. They are totally covered in black powder.

I am currently stationed in Cyprus (europe) so finding the right plugs for my engine is difficult. I just ordered plugs from summit and have to wait until Monday to get them.

I am going to try and clean and test the plugs (ohm's) and see what's going on. I also have a slight smell of gas in oil ( bore wash) so definitely i am misfiring. All my cylinders have 160 compression so my rings are fine. And my timing is spot on.

Beats the hell out of me. I'll try running engine with no stat and see but how would I get the air pockets out? Where would the air pockets be? In intake?

fastbackford351

What service are you in that you are stationed in Cyprus? Looks like it would be a pretty sweet duty assignment.

CyprusMustang

Ok update,

Since I have nothing else to do but wait for my new spark plugs I decided to test the old ones.

Cylinder 3 spark has no reading on the multimeter so it's 100% shot. Cylinder 7 has a high reading 7500 on the 20k setting and it's showing its not 100% grounded so I'm assuming it's on its way out.

So my engine was running with one cyl less and one cyl poor. Could this cause a problem with the coolant and knocking noise??