MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Tomm on August 23, 2013, 01:01:53 am

Title: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 23, 2013, 01:01:53 am
Hey guys

Need some help
my 06 gt tdi has has had a coolant leak for a while. The coolant bottle goes right down every couple of weeks or so. I have put a cardboard under the car to find where the leak is but nothing drips.

Ive also had the following checks done by my friend

egr cooler valve inspected and tested
coolant system pressure test
radiator check
pipes checked if anythings leaking
basically wherever the water runs my mate has checked but cant find the problem.

What really worries me is if the water leak is in the engine :(

i dont know if i should go to the vw dealers?

what should i do ?

please help

thanks
Tom

Title: Re: coolant leak but dont know where water is leaking :(
Post by: mortygttdi on August 23, 2013, 03:56:24 am
The bkd 140pd engine has a problem with heads going porous, its not all engines but its been seen more frequently now. 1 of 2 places the coolant goes

1) the coolant drops into the cylinders through small cracks in the head usual when stood overnight and burns off has steam when you start the car up.

2) the coolant goes through into the egr cooler at the back of the engine and drops into the exhaust and again just burns off has steam.

You would need to do a pressure test and leave it overnight to see any losses has a quick test will not show up.
Title: Re: coolant leak but dont know where water is leaking :(
Post by: vRSAlex on August 23, 2013, 07:40:31 am
Even a pressure test doesn't always show where a leak is.  Generally on these the Egr cooler would be the issue. Its worth bypassing that as a test.
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 23, 2013, 01:25:56 pm
The bkd 140pd engine has a problem with heads going porous, its not all engines but its been seen more frequently now. 1 of 2 places the coolant goes

1) the coolant drops into the cylinders through small cracks in the head usual when stood overnight and burns off has steam when you start the car up.

2) the coolant goes through into the egr cooler at the back of the engine and drops into the exhaust and again just burns off has steam.

You would need to do a pressure test and leave it overnight to see any losses has a quick test will not show up.

So if I was to do that what should I be doing alongside that to find the leak ?
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 23, 2013, 01:27:19 pm
Even a pressure test doesn't always show where a leak is.  Generally on these the Egr cooler would be the issue. Its worth bypassing that as a test.

My mate took of the egr cooler valve and it looked fine, he also got it tested and it came back fine
Title: Re: coolant leak but dont know where water is leaking :(
Post by: mortygttdi on August 23, 2013, 09:37:15 pm
Has Alex says bypass the cooler at the back not the EGR valve at the front, its easy to do but you'll need quite a bit of stuff removing to get to the pipes at the back of the engine.

Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 24, 2013, 01:16:14 am
guys the egr valve that is behind the engine is the one that my mate inspected and got tested by our local radiator specialist. Who told us it was perfectly fine. Really dont know what to do :(

think i might just have to take it to dealers :(
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Andy on August 24, 2013, 01:21:32 am
as mentioned its possible it might be a porous head
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 24, 2013, 01:26:26 am
as mentioned its possible it might be a porous head

is that a big job to repair? what is the best way to know if its a porous head?

thanks
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Andy on August 24, 2013, 01:39:22 am
as mentioned its possible it might be a porous head

is that a big job to repair? what is the best way to know if its a porous head?

thanks

it is a big job as the cylinder head has to be removed and sent away to see if there is any cracks in it...Check the other possibilities first
Title: Re: coolant leak but dont know where water is leaking :(
Post by: mortygttdi on August 24, 2013, 03:03:50 am
Could also be a damaged head gasket?? When Darkside Development took the head off mine to replace it the head gasket had gone between cylinder 2 & 3 you could see where the cylinders where wet wet with coolant.



Title: Re: coolant leak but dont know where water is leaking :(
Post by: swedishfireball on August 24, 2013, 12:35:57 pm
Can you run some dye through the coolant system? At least you may spot a dried residue as if it is leaking when everything is hot/expanded then it could be burning off almost as soon as it leaks.

Could be water pump seal/impellor or believe it or not the thermostat. Mine eas losing 100ml a week due to a knackered thermostat which turned out to be very awkward to diag due to only happening when warmed up and the seal expanding.

Good luck and I hope it's one of the easier/less costly issues.
Title: Re:
Post by: jason_rmh on August 25, 2013, 08:28:11 am
Just a thought...
I replaced the radiator on my brothers mk5 a few weeks back and that had a few leaks that weren't noticeable when it was on the car.
There were small pin hole size leaks in the rad core on the front side that you can't see as the bumper is in the way.
Also a leak from the lower rad pipe, bottom right side as you look at the car, replaced the o ring inside the plastic connector to sort that.

May not be your issue, but worth mentioning.

Jas
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 25, 2013, 04:25:22 pm
thanks foe all the help. The radiator has been inspected and looks ok :S
i spoke to darkside and told me i should remove the egr cooler and see if that helps. Is their any down falls to doing that? i was planning to remove the egr cooler and replace it with a pipe and let the car run for a while to see if it sorts the problem. Should i do anything else alongside that?
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Andy on August 25, 2013, 04:39:38 pm
if your removing the cooler then you may as well remove the egr as well
Title: Re:
Post by: jason_rmh on August 25, 2013, 05:40:42 pm
I'm doing egr valve & cooler removal tomorrow so will put a guide together although its not too difficult to do anyways.
Jas
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Andy on August 25, 2013, 08:09:25 pm
I'm doing egr valve & cooler removal tomorrow so will put a guide together although its not too difficult to do anyways.
Jas
Just read your build thread on tdi sport..Excellent mods you have donee.Look forward to the egr cooler removal as thats the next step am doing
Title: Re: Re: Re: coolant leak but dont know where water is leaking :(
Post by: jason_rmh on August 25, 2013, 10:28:23 pm
Just read your build thread on tdi sport..Excellent mods you have donee.Look forward to the egr cooler removal as thats the next step am doing
Cheers ;-)
Title: Re:
Post by: sootpig on August 25, 2013, 10:31:10 pm
I'm doing egr valve & cooler removal tomorrow so will put a guide together although its not too difficult to do anyways.
Jas
:happy2: :popcornsoda:  looking forward to this
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 26, 2013, 01:28:21 am
if your removing the cooler then you may as well remove the egr as well

i was told to take the egr cooler off and leave the valve. To see if its the egr it self. Do you think i would need to do anything else ?
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Andy on August 26, 2013, 01:42:00 am
could leave the egr on as that way your not spending money on some thing that isn't causing it to leak
Title: Re:
Post by: jason_rmh on August 26, 2013, 10:48:04 am
Egr cooler removal is quite cheap. Approx £13 for the water coupling and about an hour to do it
;-)
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on August 26, 2013, 01:22:53 pm
cars going into the garage on tuesday. il keep use guys updated.
Title: Re:
Post by: jason_rmh on August 27, 2013, 12:31:21 am
Today I did egr delete but not cooler, will hopefully get to it this week. I'll get a guide together shortly.
Jas
Title: Re:
Post by: Tomm on August 27, 2013, 01:32:58 am
Today I did egr delete but not cooler, will hopefully get to it this week. I'll get a guide together shortly.
Jas

I would imagine you would need to map the egr out of the system. Is that expensive ? If my egr is bad I'm a better of just replacing it with a new one rather than deleting it?

Thanks
Title: Re:
Post by: jason_rmh on August 27, 2013, 03:55:37 pm
You can physically remove the egr by installing a delete pipe. This causes the ECU light on the dash. That's what needs mapping out (on its own will cost around £70) plus £80 for the egr delete pipe. Still cheaper, and more reliable than a new egr valve.
Title: Re:
Post by: jason_rmh on August 27, 2013, 03:56:08 pm
PS. You can drive with the ECU light on as I am until you get it mapped out
Title: Re:
Post by: jason_rmh on August 31, 2013, 09:38:02 am
I've done my egr removal. Will get a guide done this weekend.
Jas
Title: Re: Re: Re: coolant leak but dont know where water is leaking :(
Post by: jason_rmh on August 31, 2013, 09:38:59 am
cars going into the garage on tuesday. il keep use guys updated.
How did you get on at the garage?
Title: Re: Re: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on September 02, 2013, 01:18:20 pm
cars going into the garage on tuesday. il keep use guys updated.
How did you get on at the garage?

they have bypassed the egr. I dont know exactly what they have done but said they have connected a pipe. I am going to keep analysing the coolant level.
Title: Re:
Post by: jason_rmh on September 02, 2013, 02:23:44 pm
If they have bypassed the egr cooler, but left egr valve active, its not a clever move.
Granted the egr cooler may be leaking but its job is to cool the exhaust gases before they go back into the inlet.

Egr is only used a low revs though so maybe not a major issue.
I'm doing the write up on egr removal this week, did it last week on my car.
Jas
Title: Re: coolant leak but dont know where water is leaking :(
Post by: jason_rmh on September 05, 2013, 11:28:40 pm
Took me a while to write up... but here it is!!

How To: EGR Valve / EGR Cooler Delete Mk5 TDI (BKD / BMN) (http://www.mk5golfgti.co.uk/forum/index.php/topic,72241.0.html)

Jas
 :happy2:
Title: Re:
Post by: Tomm on September 16, 2013, 01:05:42 am
If they have bypassed the egr cooler, but left egr valve active, its not a clever move.
Granted the egr cooler may be leaking but its job is to cool the exhaust gases before they go back into the inlet.

Egr is only used a low revs though so maybe not a major issue.
I'm doing the write up on egr removal this week, did it last week on my car.
Jas

Sorry I'm not really good with the mechanical tech. Just stating what the garage is telling me. So your saying that what they have done may not show if the egr is leaking ? Confused :(
Title: Re: coolant leak but dont know where water is leaking :(
Post by: Tomm on September 16, 2013, 01:09:52 am
Looks like their may be some bad news for me. Water leak has not been found. We are thinking its a porous head. Also I'm noticing the car starts aggressively specially in the morning :(
The garage is going to conduct some further tests to see if the head is porous. I have been told I can get the head reconditioned ? Obviously that's the cheaper option. What if I got the head replaced, where could I purchase a head with a decent price?

Thanks 
Title: Re: coolant leak but dont know where water is leaking :(
Post by: mortygttdi on September 16, 2013, 02:00:16 am
A new head from VW is around £1200 but that doesn't include any thing else such has gaskets or replacement bolts and seals...Speak to Ryan at Darkside Development that is who was doing mine when I had my golf...unfortunately the pistons where fried so I sold the car, but I'm sure Ryan or Scott can sort you out with a good price :happy2: