Author Topic: Do exhaust in coolant testers work on diesels? (Read 3591 times)

stopping · « **on:** July 30, 2008, 08:57:30 pm »

I have been having a persistent air in the coolant problem. A new head and three head gaskets and later I still have the same problem. It is of coarse it is difficult to describe due the nature of the problem. I don't think air arrives in the system during idle. You need have the engine hot and under full load.

Today I went to a mechanic friend and used a tester to see if there were exhaust gases in the air in the expansion tank... there was no chemical reaction so we presume no gases.

Do those tester work on CO or Nitrogen or what?
Can anyone think of how air could over pressurize the system without exhaust gases (head, gasket, cracked block?)

I have air in the rad every 10-20 min depending on the speed,
For what it's worth the idiot light comes on when you really boot it for while (engine max heat then near full load after) Apparently the light represents coolant over temperature but the gauge does not go past 3/4!
Today I also connected a pressure gauge to the van's heater so I could watch it under load and such. I didn't see anything really obvious. With the engine hot I removed any air that was in the system and got on the highway. The pressure gradually climbed to 11-13 psi over 5min at 100-110km/hr (65-70mph) varying with rpm.
I stopped found air in the rad when bleeding it, 1/4 litre- two cups... not much but there was no air there just 6-10 minutes earlier.

On the way back home pressure started a bit higher at around 5 psi and climbed to 14 (max on my guage) and stayed above 14 but did not blow coolant to the overflow tank. I drove for the 5+ minutes, stopped and checked again and there was the air in the bottle (exp tank) and a bit in the rad. (say 3-4 cups of air or half a litre)

Help ..... I wanted to drive to NFLD but had to turn around to try and fix this.

So.. I have installed new:
-head,
-H gskt,
-radiator,

Suspect:
-Head bolts were torqued to 49ftpds then turned 180deg no re-torque (I think they are slightly over tight for the metal H gasket)
-Blockage in the block creating a hot spot for the water to boil.
-Water pump might be sucking in air but not leaking water!?

jtanguay · « **Reply #1 on:** July 31, 2008, 07:37:12 am »

so does it have the oil cooler? that could be your problem...

stopping · « **Reply #2 on:** July 31, 2008, 11:19:09 am »

Yes it has the water to oil cooler but there is no oil in the coolant. Do you think oil would show up?

If it is possible for the oil cooler to such in air while the system is under pressure is it also possible for the water pump too do the same?

I know these are long shots but the problem is strange not just to me but to any mechanic that tries to fix it.

dieselwagen · « **Reply #3 on:** July 31, 2008, 12:15:18 pm »

Quote from: "stopping"

Today I went to a mechanic friend and used a tester to see if there were exhaust gases in the air in the expansion tank... there was no chemical reaction so we presume no gases.

Do those tester work on CO or Nitrogen or what?
Can anyone think of how air could over pressurize the system without exhaust gases (head, gasket, cracked block?)

On the way back home pressure started a bit higher at around 5 psi and climbed to 14 (max on my guage) and stayed above 14 but did not blow cool

So.. I have installed new:
-head,
-H gskt,
-radiator,

Suspect:
-Head bolts were torqued to 49ftpds then turned 180deg no re-torque (I think they are slightly over tight for the metal H gasket)
-Blockage in the block creating a hot spot for the water to boil.
-Water pump might be sucking in air but not leaking water!?

you could have a number of problems happening at once.
if that's my car i'd do compression test and cooling system pressure check.

i have seen old mechanics put on a sniffer inside the coolant recovery tank to measure amount of hydrocarbon to check for cracked block, cyl. head to block seal problem or even bad headgasket.

stopping · « **Reply #4 on:** July 31, 2008, 02:52:32 pm »

Yes thanks for the reply.

I did a compression check and all pistons are at 410 psi plus. The coolant system is holding pressure it seems (I have a gauge on all the time these days so I can watch). It holds 10-12 psi for 20 minutes minimum when it's hot. I think that's ok.

Yes we did do a "sniffer" test and that's why I need help. The test says no leak of exhaust gases into water system.... hydrocarbon et al I guess. If I believed it was a head gasket I would fix it(again) or have it fixed.

Thanks for your ideas

stopping · « **Reply #5 on:** July 31, 2008, 04:14:56 pm »

All right problem solved....

I need a new engine.

We did another sniffer test after driving it for an hour at highway speeds, bled the pressure off from the rad and stuck the tester in the expansion tank. During idle the test picked up the scent of a leak right away. Like I said it only leaks when it's really hot and under load.

Either I was sold a bad head (good chance cause it was cheap) or the block is cracked.

Or the head gasket job was bad but that would make three jobs done bad and I don't think I am that clumsy.

Thanks for you help... looking for a new engine

Black Smokin' Diesel · « **Reply #6 on:** July 31, 2008, 05:53:24 pm »

Quote from: "stopping"

All right problem solved....

I need a new engine.

We did another sniffer test after driving it for an hour at highway speeds, bled the pressure off from the rad and stuck the tester in the expansion tank. During idle the test picked up the scent of a leak right away. Like I said it only leaks when it's really hot and under load.

Either I was sold a bad head (good chance cause it was cheap) or the block is cracked.

Or the head gasket job was bad but that would make three jobs done bad and I don't think I am that clumsy.

Thanks for you help... looking for a new engine

I would try to retorque the head before anything else. When I did the HG in my 1.6TD I installed a metal HG. After a few thousand kms it sprung a small leak near cylinder #1. After retorquing the headbolts the leak dissapeared. Some of the bolts were uncomfortably loose :?

stopping · « **Reply #7 on:** July 31, 2008, 09:41:02 pm »

good point!

At the risk of breaking a bolt what should they feel like as you torque them at 1000?

Also I have the metal gasket so it called to torque in stages up to 49ftpds then turn 180deg. Is that right? No re-torque when hot... no re-torque at 1000? (Non stretch bolts as far as my parts guy could tell.)

Riverfurm · « **Reply #8 on:** August 02, 2008, 06:47:39 pm »

http://riverfurm.smugmug.com/gallery/5602298_SECiE#343803787_3Dxsf-A-LB

This is what I found with the same problems you are having.

stopping · « **Reply #9 on:** August 05, 2008, 11:50:48 am »

I have been looking for that... if I have it it would be small and, I think only seen by magnaflux. Where is this on the block... seems like it`s on the out side looking in!

I am on the road now traveling very slowly toward Newfoundland and the same troubles are happening.. the difference is if I drive at 90 km/hr only, the system sort of works, the engine is too hot for the highway but does not overheat..... there is no oil in the coolant.... and I don`t know if there are still exhaust gases getting in the the system but feel the need to indulge in other unlikely senarios.....perhaps the oil cooler is not cooling properly?

jtanguay · « **Reply #10 on:** August 05, 2008, 11:57:54 am »

the oil cooler acts more like an oil warmer... if the engine runs better when cool get yourself a cooler thermostat so you can get to where you need to go and fix it there.

there's also a way you could rule out the oil cooler... and its by looping the coolant lines going to the cooler. you need a coupler and some hose clamps. :wink: without the special tool though, the stock clamps are such a PITA to get off!!

Riverfurm · « **Reply #11 on:** August 05, 2008, 05:22:13 pm »

Quote from: stopping

I have been looking for that... if I have it it would be small and, I think only seen by magnaflux. Where is this on the block... seems like it`s on the out side looking in!

It's on the front outside of the engine behind the IP bracket. It started with a coolant leak, then the engine would run warmer then normal and foam up the coolant. Then it just overheated. Waiting for a short block from PartsPlace.

By the way..... has anyone have any dealings with Partsplace Inc. They are putting a shortblock together for me and stated it would take three weeks. I contacted them twice (they have a $500 deposit) and they seemed annoyed. It was three weeks last Thursday.

stopping · « **Reply #12 on:** August 05, 2008, 08:35:25 pm »

I think I am concidering waving a chicken over it.

I see no crack I have had several oportuities to look carfully.

I will be trying to diagnose the problem but I am pretty much resigned to changing the engine. I will have to stop my trip, leave the van here at my friend's and jump on a freight train.

If you have any tips for checking the water pump, oil cooler.....etc...

I know that the surface of the block is not perfectly flat.... ie: I had to scrape and sand epoxy off the head when I first did the head and it may have rounded the surface too much.... the thing is the last head gasket had signs of a leak at the fire ring but the leak was around the corner of number one around the oil gallery (if that's what it's called) toward the IP No oil leak into coolant at that time. I did a test recently when we did the last exhaust sniffer test and there was oil in the coolant... I torqued the head bolts a quarter turn and since then.... many times overheated and very nearly overheated..... coolant spewn out the van = overheated.

So on the last gasket job I used JB weld on the block just to fill various pits then copper silica spray then the gasket.

Any diagnostics advice? I am kind of stuck.

carrizog60 · « **Reply #13 on:** August 06, 2008, 02:53:23 am »

Quote from: "Black Smokin' Diesel"

Quote from: "stopping"
All right problem solved....

I need a new engine.

We did another sniffer test after driving it for an hour at highway speeds, bled the pressure off from the rad and stuck the tester in the expansion tank. During idle the test picked up the scent of a leak right away. Like I said it only leaks when it's really hot and under load.

Either I was sold a bad head (good chance cause it was cheap) or the block is cracked.

Or the head gasket job was bad but that would make three jobs done bad and I don't think I am that clumsy.

Thanks for you help... looking for a new engine

I would try to retorque the head before anything else. When I did the HG in my 1.6TD I installed a metal HG. After a few thousand kms it sprung a small leak near cylinder #1. After retorquing the headbolts the leak dissapeared. Some of the bolts were uncomfortably loose :?

isnt the metal hg one time torque stuff?
i have a small leak when the engine get colder but water gets outside...
could be othr stiff but i could try retorquing the head also...

what values did you torque it?

max and caddy · « **Reply #14 on:** August 06, 2008, 06:22:12 pm »

ummm... i dunno if this will help but a few years ago i had a passat with a similar problem and it turned out to be the top rad hose, it had a small pipe coming off it to the header tank and where it joined the main hose there was a plastic bit inside, like a a elbow type thing, that was blocked up so i pulled it out and no more probs, car would run fine for miles then suddenly loose a load of water, cool down, top up, fine again. just a thought.