Diagnose my 4age, with videos!

[Mitchee]

Okay so I think its finally bit the bullet on me. I knew it was on its way out, and I know its definitely gone now, but I'de like a 2nd opinion on how 'gone' she actually is. What do you guys think?

http://members.optusnet.com.au/dmspc1/ae82-1.mpg - 5.2MB
http://members.optusnet.com.au/dmspc1/ae82-2.mpg - 2.8MB
http://members.optusnet.com.au/dmspc1/ae82-3.mpg - 2.2MB

1. When its running, and the water is cold, a small amount of steam comes out of the radiator cap, this seems to slow/go away when you free rev her for a couple of minutes.
Once it warms up its bubbling out of the radiator cap constantly.
Does this suggest the headgasket is broken and exhaust is escaping into the cooling system?. Would this also mean its pressurising the system when the radiator cap is on, and pushing all the water out to the overflow tank?
Theres also a small amount of steam coming out of the exhaust, which you can see in the videos.
With the radiator cap on, there is never any hot water in the top hose.. Is this water pump? Thermostat not opening?

2. Massive blowby. Take the oil cap off while its idling and theres huge pressure coming out of there. Take a look at the video and you'll see just how much its blowing out of there. Is this rings?

3. Once I turn her off, theres a bubbling noise coming from the 'back' of the engine, just near the thermostat. Ahh ok... Overheated, but its only been idling in my driveway.. My thermo fans have worked properly in the past.

[TC1600]

1. Firstly, a small amount of steam out the exhaust is normal. For every litre of fuel burnt, a litre of water comes out (apparently), mostly as invisible vapour. When the engine and exhaust are cold, the water condenses inside the exhaust system, then as it warms up it evaporates and steam comes out. when it is fully warmed it doesn't condense and just comes out as invisible vapour. As to the bubbles, it does look like a BHG, combustion pressure means that combustion gases go into the cooling system, and work their way to the top and escape as steam pockets.
2. Some blowby is normal on any engine, but yours does seem excessive. How many k's has the engine done? It could be getting tired. BTW, worn comression rings = blowby, worn oil control rings = smoke on acceleration. An engine with one may not neccessarily have the other.
3. the bubbling at the back of the engine is localised boiling, possibly from exhaust gases getting in to the coolant, or a stuck thermostat or failed water pump (especially as the top hose is staying cold). If you are rebuilding the engine it's usually good practice to replace the thermostat and at least inspect the water pump (but i'd probably replace it to be on the safe side.)

Hope this helps.

[fixeruperer]

could be airlock try bleeding the system or if you know anyone that can let you borrow a tk(co2) tester that will tell you there and then if its a gasket, take a heater hose off the firewall and run fluid threw the rad till it comes out the heater hose and core making shaw your heater tap is open.

[DX20VT]

I'd be guessing on a air lock first too.

I usually put a hose in the radiator and just leave it flowing a bit, ( will overflow so do it outside)
remove the heater hose and you should get a good flow out of one of the pipes.
Then block that pipe off and it should start to flow out of the other one.

Then re-assemble and then pull out the hose.

I know that with my RWD 20V setup, if you did not bleed and get water to the engine side of the thermostat, it would not open to let the air escape so it would not self bleed.

[LeeRoy]

Thats not blow by either. My 4age spits out heaps of oil when you open the oil cap but only cause youve got camshafts coated in oil that are spinning and flicking the oil off. Think of if you were to throw a hose onto a spinning bike tyre - the same thing would happen.

What you need to do is to get a compression tester and test all cylinders. Then you need to see if your getting any exhaust stuff or oil in your coolant. Finally check your oil and see if its milky which would indicate it is mixing with coolant.

And fix that nasty top radiator hose that runs between the distributor and the leads. Looks like you have the wrong radiator and that looks dodgy as.

[Mitchee]

Hmm, mixed assumptions from a few people it seems...

I took a look inside the radiator after it cooled down and i couldnt see any water in there at all, could this be the steam pockets going away once the engine cools and the water flowing back into the engine?

I'll comp test it this arvo and let you know the results. The radiator is fine, and was recently reconditioned, the top outlet snapped slightly hence the clamp close to the end tank. It holds pressure fine.

There is a very small amount of froth under the radiator cap and the oil cap also. When I say small amount i mean just around the edges of the inside of both caps. Its definitely water & oil.

Anyway im just going to replace the engine completely, cant be bothered pulling it out and frantically rebuilding it trying to get the car back on the road. See signature.

[LeeRoy]

Blow by is where pressure is passed through the crankcase after being built up by the movement of cylinders. It normally passes through the pcv valve in the form of an oil vapour causing your car to smoke. Oil spitting out of a hole comming from a spinning camshaft is not blowby.

When you comp test you should get the same or similar readings across all cylinders. Also have a look down the back of the engine and see if any coolant or oil of anything is leaking out of the hg. That might explain the bubbling noise.

I didnt mean there is anythhing wrong with your radiator but the top hose running between the dizzy and the leads looks dodgy as fuck and id be changing it asap (either the hose or the rad).

Correct me if im wrong but arent your cam covers red and black ie its a smallport?

[Mitchee]

Ah ok. I assumed excess pressure out of the oil cap = blow by.

I'll take a closer look at that hose when I get home, im sure its ok.

Engine is definitely a bigport, unless someone has somehow adapted tvis to a smallport and given it a 3 rib block! Its got the blue writing on the cam covers too.

[LeeRoy]

Yeh cool as. Ive seen the same top radiator hose before on another guys car on here and it just worries me. A hose really shouldnt run between the dizzy and the leads.

Looked smallport to me but guess im wrong. Swapping an engine wouldnt be too hard and probably on the same level as fixing your motor if its stuffed. If it is a hg your prob better just replacing the motor but at the same time for less than $200 provided your pretty handy under the hood and you have the right tools you could do a new hg and full head rebuild.

Did you cook the motor previously?

Edit: I actually went out and checked my car about the oil cap thing and mine does the same thing. It also spits out a fair bit of oil but like i mentioned before thats just comming off the cams. The cap bounces around a fair bit but my hg is fine cause i changed it less than 20,000k's ago, car doesnt burn or lose oil or coolant.

[Mitchee]

The hose running under the leads is actually factory. Here is the bay of another ae82, http://img61.imageshack.us/img61/627...02006137bc.jpg

Not sure if the engine was fried before I got it. Its always been a bit funny with temps, randomly heating up a bit more than normal every so often. It was never a concern. Oh well, I think I might have found an engine. *crosses fingers*

[LeeRoy]

If its factory then its a worry

[TC1600]

Its factory, and its not one long hose, the bit behind the dissy/leads is a metal pipe. one hose goes to the rad, the other hose goes behind the engine.

[Cuzzo]

Try doing a compression test on all cylinders.

You will see why you are having so much blow-by. Thats a fair bit to put oil on your hands.

To "bleed" the water system. Put a coke bottle with the bottom cut off like a funnel in your radiator where the cap goes. If it doesnt quite fit put some tape around it to keep it tight.

Turn on the fan and put it to heat. Warm the car up whilst filling the radiator through the coke bottle so that the coke bottle is holding some of the water and the radiator isnt taking anymore water in.

The idea behind this is to raise the highest point of the cooling system and with the engine running the air will bubble out hopefully getting rid of all the air.

[Mitchee]

Looks like I should have a shiny new (used) 4age on its way to me sometime soon!

Ahh thats a great method Cuzzo. Ive heard the 'park on a steep driveway' method, but this makes more sense.

[hemi twofifteen turbo]

it definalty looks like head gasket, as a quick test remove the thermostat completly, then refill the radiator, then run engine with hand over the radiator cap hole and block off the little overflow pipe line. Rev, and lift hand on and off to see if there is pressure there from combustion gasses. This is also a dodgy fix to get you out of troble if you blew a head gasket on a long trip, just leave the radiator cap loose to allow the combustion gasses to leave without pressurising and expelling the water. Hope this helps!