Suspected Head Gasket / Water Pump failure

Aug 12, 2019
3
0
Hello all,

Just looking for some second thoughts on vehicle woes. I have suspsicions but it woudl be good to get some other opinions. Vehicle is a 2003 SEAT Leon TDI SE (110).

Symptoms as follows:

  • Ongoing Coolant loss (on-going - but significantly reduced if I release coolant tank pressure after each drive - current management process!)
  • Coolant tank pressurised when left to cool (ie. day after driving.)
  • White smoke from exhaust when on high boost (~ 3/4 or more throttle)
  • Engine ran cold over winter (not unusual?) and doesn't overheat - maxes at 90/92 degs (vertical)
  • No white sludge in oil or visible oil notes in coolant.
  • Rad fans don't activate at high temp, but haven't seen high temp yet so believe this is normal behaviour. They do appear to run when the aircon system is active (again normal behaviour I think)
Vehicle is due cambelt soon, so wondering if I just bite the bullet and get the head gasket replaced at the same time. Labours going to hurt!

Does anyone have any other thoughts on what could be the cause?

From what I've read, it's likely to be either HG blowing into coolant and pressurising; or water pump failed (although I'm not sure how this would pressurise the system to such a degree).

Any opinions gratefully received.

Thanks,
Dan
 
Aug 12, 2019
3
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I haven't enquired about a price just yet, no. Just thought I'd see if anyone had seen similar symptoms on cars previously that could relate.

Everything I've found pointed to one of the two issues noted above.

Fans were more of an observation, I don't believe are at fault; they work when activated by the aircon system as intended, but the engine never gets warm enough to trip them.

Only seen it hitting 90 in the recent warm weather - anything above about 18 degs ambient seems to enable the temperature to climb but it stablises once there.
 

sockpuppet

Active Member
Apr 30, 2007
837
4
Had the same thing on my diesel, I was convinced it was head gasket as I got oil in the water, everything pointed to the head gasket, but it was the water pump and the head gasket was fine. It took months for the water pump to go completely, it would work fine for days and sometimes weeks with no coolant loss or anything in the coolant. The annoying thing was that the water pump was a patent part and only did 40000 miles before beginning to fail, the previous 4 water pumps were all genuine parts and made it to 60000 miles each
 

chriswales6

Active Member
Mar 2, 2016
294
47
I also have a 03 TDI SE, my first guess would be the water pump. The 110 are strong engines and don’t normally have head gasket problems unless its overheated or been running stupidly high boost.

You can test the water pump by removing the return line to the header tank. It’s the small pipe that connects to the top right hand side. Put the pipe into the top of the bottle and start the engine. There should be a steady flow of coolant, if it stops and starts then the pump isn’t very well. There’re videos on you tube showing what a normal coolant flow should look like.
 
Aug 12, 2019
3
0
Hi all;

So brief update - now suspect it is neither head gasket or water pump....

Replaced the thermostat, which appears to have resolved the cold warming issue - assuming that was a failed thermostat (Which seems to be a common problem on these cars).

On giving the car a quick service pre-MOT, identified the undertray was damp on one corner, so current suspicion is the radiator is leaking. This would make sense given that relieving the pressure post-driving results in significant reduction in fluid lost.

Slow start on start-up seems to have been improved by new glow plugs; again as expected.

So going to go hunting for a new radiator - will see from there!
 
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