Look for a odd coolant leak !

[MAXIME]

Hi Guys,

I’m a french guy, so would you excuse me for my language n vocabulary fault, :dry: , when i will trying to explain you my issue.

My car is a VW Golf 1997 1.9 TDI with 1Z motorisation 90ph

And as like the title of the topic tell you, i’m looking for a coolant leak.

Let me explain what happen :

The issue start by a red light blinking on my dashboard couple weeks ago, after a trip of 600 miles (1500km), so i thought its due to the season and its high temperature (summer) and the long trip.
So i add some coolant in the expansion tank, and i think it s OK.

Some day after i ve the problem again and again, so i keep an eye on the expansion tank, and i notice that :

Sometime, when i going to take my car to go to work for example, i fill the expansion tank in the morning.

When i take my car to go back to my home, i check the tank again, it seems to be OK, filled to the right level, i start the car and go away, after just an half mile, my warning indicator blink start blinking.

This situation going worst to worst, day after day, now, i have to fill it on the morning and check it in the evening when i go back to my home after work and by the way fill it again.

I have to mention this, i thought i found the leak once so i changed the hose who linked the tank an the rest of coolant circuit.

After that i ve got the same issue so i changed the tank without its cap, same issue !

After that i decided to change the cap because i thought the circuit got to much pressure who could not be released by cap issue, cap spring or cap system fault.

So i hope, my explanation is not so misunderstandable and my english writing is acceptable…

Thanks for the help and your write back in advance 🙂

JM

Topic

[MAXIME]

I think about buy a circuit coolant tester, it would make the circuit under pressure.

What do you think about that ?

[Lorrin Barth]

Yeah, put about 15 psi of pressure in the cooling system and see if it will hold that pressure.

[EricTheCarGuy]

It sounds like you might have a leak somewhere. You will need a special adapter for your vehicle but you can perform this test to find it.

You can find additional information on how to solve issues like this here.

http://www.ericthecarguy.com/faq/what-to-do-when-your-engine-overheats

Good luck and keep us posted on your progress.

[Quincy]

HI John-Max,

How many miles or kilometers does your engine have? I was thinking you could check the thermostat by seeing if the upper radiator hose gets warm to hot when engine is warmed up, but it sounds like you continually have to add coolant which means either an external or perhaps in this case an internal coolant leak. Redline makes a good coolant system pressure tester in which the attachment fits inside the neck of the expansion tank and expands, this is the one I have. You can also try checking the oil dipstick for signs of coolant contamination but this doesn’t always work especially if the coolant is getting sucked right into one of the combustion chambers. A compression tester might also help to find a leaking head gasket, you may have to warm up the engine first and then try it. Check the smell of the exhaust gases from the muffler, does it smell sweet or look foggy/ humid? To assist in locating a difficult leak, you can also purchase UV dies especially made for coolant systems and the special light to detect it for around $50. Let us know how you make out!

[Tom]

When I had a bad head gasket in my Honda, it about drove me crazy. I was losing coolant, and had that sweet smell on occasion in the exhaust, BUT .. .

Compression was very good across all 4 cylinders, well within 10% of each other, almost unbelievable for an engine with near 200k miles on it.

Cooling system passed a pressure test with flying colors.

No signs of oil in coolant.

No signs of coolant in oil.

I never really saw bubbles in the coolant with the radiator cap off and the engine running.

I finally verified the head gasket leak when I fired the engine up with the pressure tester attached to the radiator, and the pressure immediately shot up, way up. At that point, I knew there had to be combustion pressure getting into the cooling system.

[MAXIME]

@Everybody/@ETCG

Thanks a lot, for all of your response, and thanks to Eric for all of your video, and for sharing all of knowledge.

I going to take 1 week vacation, soon as i came back, i m going to buy that coolant circuit tester and do some test.
So i keep you informed about that.

I hope, it s not a head gasket :ohmy: !

@Trod
My engine have about 310000 km so i guess it s 160000 in miles measure.
Yes when i touch the upper hose who connected to the radiator it s hot.
No coolant sign when i look to the oil dipstick, no oil sign in the coolant expansion tank.

Please follow my topic, thanks in advance.

@Tomh, I m starting to going mad about that 😀
By the way, your description seems to be close of mine, we’ll see the result of the coolant pressure test

[Stephen Bowen]

Look under the car and see if you notice any wet spots? VW’s have a couple of known oddities with the water pumps where it will look like it’s coming out of the crank pulley. Of course they also use a lot of plastic pipe work for the attachments to the block/head. They are known for cracking at times.

I hope you are filling it with the correct coolant made for VW’s. It used to be G12..but it’s been replaced by G13. I get shouted down for this a lot, but using any “universal” or “Green” coolant can do severe damage to the engine. (I also do work on a VW Beetle Forum. And we see a lot of TDI’s with coolant leaks. Same exact engine as yours.) Mixing the coolant with green creates a reaction that starts to make a white ‘crust’ snot material in the passageways. One member recently had some severe blockages he had to clear out for this reason.

Best suggestion would be to park the car over a sheet of cardboard. Start the engine and let it idle. And from there? Look for any drips. Also check your oil for any milk like residue. This can also point towards internal leakage. (don’t bother checking your oil fill cap–that can have a milk texture to it from unburned off condensation. Check the oil on the dipstick. Milkshake appearance=bad news)

From the sounds of the leak, if it’s a leak? It should present itself. If you loose coolant and see no signs of any dripping or smoke from the engine compartment (would point towards dripping onto exhaust parts)–Then I would start to consider internal leakage, such as head gasket.

S-

[MAXIME]

Hi guys i m back, what a good holidays, so i just receive my coolant system tester, i put my circuit under pressure with that tester :

http://ecx.images-amazon.com/images/I/41GJVfnhA%2BL.jpg

I put 22 psi pressure, no leak found…

I do it n do it again, no leak found…

I going to drive my car in high rpm to see, if my problem came back again …

Keep in touch 😉

[EricTheCarGuy]

At least now you know the system can hold pressure. You might replace the radiator cap for good measure. Sometimes they go bad and allow too much coolant to exit the system when it gets hot. It’s an easy repair and doesn’t cost that much.

Good luck and keep us posted.

[MAXIME]

I m back again, i just change my phone so i was able to do a video who show you what happen, i have something new to tell you, i ve got a real waste of my coolant when i stop my engine.

I m at work, I m going to post my video when i m back…

Keep U in touch

John

[MAXIME]

Another thing i want to add : I have no radiator cap, i going to post a scheme of my coolant system from my Car Technical Book.

[MAXIME]

Like i said please find my video … To see what happening to my VW

:S Didnt undestand :S

If you have an idea … Let me know …[video width=550 height=309 type=youtube]VnLTA4mXIf0[/video]

[MAXIME]

There is the scheme…

Attachments:

• schema.jpg

[Shane]

Looks like coolant is not circulating through the engine block, might want to replace your thermostat, either that or the radiator may be blocked. Thermostat is usually very cheap compared to a radiator.

If you run the engine for a while and touch the radiator hoses they should both be warm. If one is hot and one is cool then you have a problem.

Also, with a closed system like this it is possible to have air stuck in the system somewhere that can cause similar symptoms, to fix that you just need to flush the system then refill with coolant.

Now that I got home and listened with my nice headphones, you can actually hear the coolant bubbling as it goes down in the reservoir. I think you may have air in the system.

[MAXIME]

Hi, Shane940

All of the hoses are warm around my radiator.

For the bubbling, yeah I hear it too, I had to flush the system for a while but i didn t 😆 .
That maybe will be the first step to do, regarding my issue, such a biigg mistake of mine :whistle: .

I m going to do it as soon as possible.
I hope that will resolve my issue.

Keep in touch

Thanks

[Author]

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