Intermittent Rise In Coolant Temp - Newbie

[Yozza]

Hello, this is my first post on this forum so apologies if this topic has already been covered.

 

I recently bought a '02 Ghia Mk2 1.9tdi with 124k on the clock (with FFSH).  It has a few issues (all of which I'm hoping are relatively minor).

 

The most pressing issue is an occasional rapid rise in coolant temp,  during all instances I have been on the motorway and well into my journey when the needle will rapidly rise up to the red marker, I reduce speed to 50mph and the temp will rapidly fall back to nominal (90 deg), it has occurred 3 times over the space of 400 miles.  Coolant levels are ok.

 

It had a new water pump not that long ago so it 'shouldn't' be the impeller spinning on the shaft issue which I've read about on here?

 

I'm really hoping it's not the head gasket because it happens so infrequently.  My thoughts are a dodgy stat or maybe an airlock being moved or sediment that temporarily obstructs the coolant flow?

 

Can any of you Galaxy mentors suggest a possible root cause?

 

Thanks,

Yozza (Galaxy mentee)

 

 

[seatkid]

One possibility is a cracked cylinder head - has the car been remapped or had a tuning box in the past?

 

Another possibility is a faulty thermostat and/or water pump (was the water pump an OEM item?)

[Yozza]

Hi seatkid, thanks for the reply!

 

I'm confident the car hasn't had a tuning box in the past and it's not been remapped.

 

The water pump was fitted by Frauds so it should be OEM.  I'll try the thermostat first and see how that fairs.

 

If is was something serious like head gasket or head, wouldn't I see this issue ever time I got the engine up to temp and 'loaded'?

 

I did have a closer look inside the coolant top up tank and it was looking low on coolant (I recently topped it up) and some dark residue in there.

 

Is it possible for the garage to test the gaskets integrity while it's steel on the vehicle?

[seatkid]

Did this problem manifest itself before the water pump change? If not - it could well be a warranty job.

 

I've known on my previous galaxy to have a thermostat that wouldnt close due to some black sealing gunge (from the factory) that got lodged in it. (i.e. running cold).

 

Yes I think if it was gasket/head problem it would show up regularly - but it also sounds as if you maybe be losing coolant.

[Yozza]

I'm not sure when the overheating issue started (I've only had the motor a week) but I managed to get a print out from the Fraud garage for the service history, the service says:

 

"over heating - suspect water pump" @ 117k miles

 

"engine over heating" '@ 118k miles

 

"coolant leak" @ 119k miles

 

Looks like Fraud never got to the bottom of this issue, so I'll have to fix it (hopefully).

[chrispb123456]

You say water pump has been changed previously, it may be then the damage has already been done.

pressurising and intermittent overheating are all signs of head gasket failure or even cracked head.

So any signs of excess pressure, fluctuating coolant level, intermittent heater (goes cold)

 

Also check run on pump is still working (behind fuel filter) as this aids circulation. 

[gregers]

where/who did you buy it from?

if a garage take it back to them to sort out.

if private i still think?? you may have some kind of recourse.

but check out your legal rights under the sale of goods act.

[Argrdnr]

Even if you have had the car for 3 months and it goes wrong, under the sales of goods act you can legally get the garage to fix it.

If private - not 100% sure.

[Yozza]

Ok thanks,

 

In the last few days I've bitten the bullet as I caught the temp when it was high, lifted the bonnet to find the head gasket weaping - DOH!

 

I've stripped the head off and water pump.  The pump is the plastic impeller type which I'm confident is the root cause, the sympton being a very hot block and forcing the head gasket.

 

I've checked the head with a straight edge and it looks good so I've got a gasket.  Euro do 3 thickness's, I've got the thickest one as there was some confusion about the identification marks (holes) in the original gasket, it has 3 obrounds (slots) and 2 circular holes.  The new gasket has only 3 circular holes, so I'm not sure if they are both the same thickness.  Have I got anything to lose if I fit a slightly thicker gasket than the original if I'm not having any machining done?

[gregers]

do you have any kind of warranty on this car?

if so then i think you will have invalidated it by attempting a repair.

[xavier]

Geez you don't mess about do you! I'd assume private if you're whipping the head off and having a go yourself. Sorry I can't answer your question but good luck with the repair. Would a Ford / VW garage be able to better advise maybe?

[seatkid]

http://www.auto-parts.spb.ru/cat/au/au.mycat?SelPg&t=rXSuTmV0rk49dK5O7y7Gd5w192j_LVU0HEeuTpwrLn6tdKwxTVaqQq1C6FatVK7HoCfHcwW9nCas1DsBZSWw6QkOKM28ueNf77THBmbdALWzcHfTwAYGuRw393qtvJZXvamFWpUljTodbbba7l16oePn758RpayDIjHMvbsbHDRGDX_Rd0J34rL5Z60uR0/CrowV3IS2Ksl2oSfW

 

Shows 3 thickness, and 1,2,3 hole

 

Cribbed from elsewhere....

Your engine will have a mark on it telling you which head gasket is fitted. It'll have either 1, 2, or 3 holes marked on the block to signify which gasket you need.I'm not certain where they're marked though, but I think looking from the front of the car, it's the right hand side top of the block at the front (opposite end to the timing belt). Mine has a single hole drilled there on a flat space, which I presume signifies a 1 hole gasket for me.

Edited July 8, 2013 by seatkid

[chrispb123456]

Be sure there's not the slightest distortion or erosion on the head face, check with an engineering shop that deals with machining if there's any doubt, would hate the same to happen again.

Ignore the oblong slots only holes and notches apply

[Yozza]

Thanks for all the replies fellas,  I'm now tackling another problem...

[clausbarlose]

I've had the same problems - temperature rises when driven (semi-) hard but falls again when speed is lowered. This was last winter. An authorized Ford garage initially changed waterpump and belt from suspicion without proper diagnose.

 

Garage changed fan, sensors,  checked whole cooling system but still no luck until head and gasket was changed. They had to do a compression test and found a tiny crack that was only present at high pressure (high speed/up hill).

 

Up until that, it had been leaking coolant and had these occasional rises in temperature, but problem is solved now.

 

Last week my autogearbox was repaired - gears 3 and 4 were missing and I still have have the occasional engine limp mode.

 

These repairs has cost me appr. 7.200 £ (as I'm not skilled with tools) and I'm hoping the car will stand this vacation's trip to Italy...

 

This was my two cents on the heating issue.

 

Is the ECU/pipe/MAP sensor problem also the game for MK2 Galaxy's?

Edited July 14, 2013 by clausbarlose