Author Topic: aaz building pressure in the coolant......STILL! (Read 10751 times)

giulianot · « **Reply #15 on:** February 10, 2009, 05:26:41 pm »

I agree that the t-stat installed offers better cooling control.

The used head was not pressure tested after machining because it came off a running engine, and it looked to be in good condition.

A new 2 hole V/R head gasket and new head bolts were installed when machined head went on. Bolt were torque to 30, 45 ft/lbs the 2 90 deg stages

all symptoms point to a head gasket failure but what could be causing it?

Smokey Eddy · « **Reply #16 on:** February 10, 2009, 05:28:42 pm »

:cry: ...

a warped block? :cry:

did you use a metal HG?
did you do the hot retorque?
is it 100% water?
If it persists you could try switching to studs?
I know for a fact that i would have this problem if i didn't use studs and a metal gasket

jtanguay · « **Reply #17 on:** February 10, 2009, 05:31:50 pm »

Quote from: "giulianot"

I agree that the t-stat installed offers better cooling control.

The used head was not pressure tested after machining because it came off a running engine, and it looked to be in good condition.

A new 2 hole V/R head gasket and new head bolts were installed when machined head went on. Bolt were torque to 30, 45 ft/lbs the 2 90 deg stages

all symptoms point to a head gasket failure but what could be causing it?

i will also have to add my experience with a 'bad' oil cooler. i was experiencing some weird problems with my motor after getting a new headgasket put on. there was oil getting into my coolant, and my oil level was rising. i installed a new oil cooler, drained and added new oil. problem completely went away. (there was so much pressure that my oil filler cap actually came off. not sure how, but it did. maybe i didn't tighten it down enough, but still!)

apparently VW recommends changing out the oil cooler after any major engine work... probably because of its inherent weakness?

giulianot · « **Reply #18 on:** February 10, 2009, 05:49:49 pm »

I used a metal head gasket . We did not re-torque hot I've never felt it was necessary. There is a 50/50 mix coolant and water in now.

I have seen oil cooler failures, but i dont think it is the case here. There is no oil in the coolant or coolant in the oil.

If the problem persists after the spring is installed in the lower hose than I will have to remove the head again and try a 2nd head gasket replacement.

Riverfurm · « **Reply #19 on:** February 10, 2009, 05:57:15 pm »

It's a cracked block. The Tstat control temp not prs. It's doing the same thing as before.... The head and gasket have been replaced, next is the block.

I know this because it happen to me.

jtanguay · « **Reply #20 on:** February 10, 2009, 06:21:35 pm »

Quote from: "Riverfurm"

It's a cracked block. The Tstat control temp not prs. It's doing the same thing as before.... The head and gasket have been replaced, next is the block.

I know this because it happen to me.

i wouldn't call it that just yet... remember that the AAZ head gasket must actually be deformed to work properly. if its not properly deformed, it will most likely not seal well enough. perhaps a retorque would be a good idea???

giulianot · « **Reply #21 on:** February 11, 2009, 01:33:13 pm »

So this morning we preformed a hot retorque, a ful90 deg on each headbolt in the proper bently order. Now we hooked up a pressure gauge to the coolant top hose to inside the dash so we can monitor coolant pressure in the cabin. It seems that the hot retorque did not work as the temp gauge still fluctuates +-1/4 scale under light to hard loads.

53 willys · « **Reply #22 on:** February 11, 2009, 01:38:55 pm »

it took me 110ftlbs to finally crush my MLS headgasket and stop the leaking....but that was with ARP studs not head bolts..

Smokey Eddy · « **Reply #23 on:** February 11, 2009, 04:13:14 pm »

my temp gauge will fluctuate like that. when i romp onto the onramp to the highway it'll go to 3/4 and then cool right down to 1/4 once up to speed and then gradually get to the middle.

it will really bounce back and forth with city driving too. I got a new sender, maybe it's more responsive or something? if you have the heat on you can feel the coolant get hot when you romp on it and then actually tell when it goes through the rad and cool right down. If it goes from hot to cold to hot to cold like i described perhaps blocking part of the rad with some cardboard might do the trick? so that it doesn't quite cool SO much and give lots of lag on the t-stat to open again.

just an idea... that came out of the gear that slowly turns in my head

53 willys · « **Reply #24 on:** February 11, 2009, 04:54:19 pm »

should not need to do any radiator blocking....those stock temp gauges are JUNK...my stocker reads all over the place compared to my Isspro temp gauge...the isspro holds pretty solid at 190-200* no matter what I do...the stock gauge in the mean time goes up to 3/4..then back down to 1/2.......I really would not trust the stock gauge that much..

Note I am running a cooler fan temp switch so I run slightly cooler all the time......

jtanguay · « **Reply #25 on:** February 11, 2009, 05:32:05 pm »

Quote from: "giulianot"

So this morning we preformed a hot retorque, a ful90 deg on each headbolt in the proper bently order. Now we hooked up a pressure gauge to the coolant top hose to inside the dash so we can monitor coolant pressure in the cabin. It seems that the hot retorque did not work as the temp gauge still fluctuates +-1/4 scale under light to hard loads.

did you verify the thermostat is working properly by boiling it with a thermometer?

the temp fluctuations seem normal to me (with a cool thermostat)

don't worry about the temp, unless it gets more than 3/4 on the gauge. just keep an eye on your coolant PSI.

arb · « **Reply #26 on:** February 12, 2009, 09:08:31 am »

What did you find out about the pressure your cap is holding ? Sounds like you are not over pressure but have gauge problems.

passatdiesel · « **Reply #27 on:** February 14, 2009, 09:35:27 am »

How did you make out on troubleshooting?

dillenger1 · « **Reply #28 on:** February 14, 2009, 10:11:31 am »

ive recently started using the "water wetter" performance coolant additive.and i must say its wonderfull.The temperatures are way more stable.I cant get it to move when its up to temp

stopping · « **Reply #29 on:** February 14, 2009, 12:46:11 pm »

Does anyone think blocked piston oil jet (due to sloppy head gasket replacement) could cause overheating of the cylinders and contribute to head gasket troubles?

I have noticed much higher temps around the pre-combustion chambers/ glow plugs compared to the rest of the block. A difference of 90C on the block compared with 105C sometimes at the glow plugs. The hottest measured temp being at the base of the head. I have mentioned this before but found no explanation so far. To me there should be a higher temp in the area but not that high.

The implications of this is that if the surface is that temperature the coolant must be higher. If the coolant reaches that temp at idle (I measured at idle) what happens at speed? And could it produce enough boiled bubbles that it could fill the rad or cause an air block of the oil cooler?

This might be a condition of higher mileage engines only and might not be as dramatic in newer engines.

Author Topic: aaz building pressure in the coolant......STILL! (Read 10751 times)

53 willys

53 willys

arb

stopping