Hi. My car is overheating. Iv been told to remove the thermostat and check for play in the water pump? Is it a simply undo both bolts let water come out and then stick my fingers in there? Will it all go back together ok or will I need to replace some sort of seal?

Should go back together OK but you will lose some coolant. Other than the thermostat being stuck closed (the usually tend to stick open when they go) I'm not sure what else it could be other than the water pump if you're not losing any coolant. I would try to confirm diagnosis on the water pump by ruling other things out rather than taking it apart to find out.

Only water I lose is when it boils over in the expansion tank. It overheats when accelerating. On idle and cruise it sticks to 90. Been told by most it's the water pump which I suspect it is because it's never been changed In its 143k miles liFE. For some reason the previous owner didn't change the water Pump.

If you get water through the top hose back into the expansion bottle when idling then the thermostat is probably OK what you will probably find is that under extreme load the impellor on the waterpump will be slipping on the spindle in the waterpump itself .

 

When was it last changed (along with the timing belt)?

I don't believe the water pump has been changed. Cambelt is due next January.

Will water run through the top hose all the time or only when up to temp?

You might be lucky though as I had similar problems last year with a saab 9-5. Overheated on M1 so pulled over all went fine. Temp vack in middle at 90 i drove 1/2 mile and overheated again lost most my coolant out of the bottle covered bonnet.... AA came and took thermostat out and lucky enough it was jammed shut. Replaced and never had a problem in the following 4 months of owning it and about 5,000 miles after

only when up to temp as it's in the return feed after the thermostat.

 

If it is the waterpump you may as well get the timing belt done at the same time (remembering to get the tensioner kit as well as the belt)

Just went through the cars history. It's still running it's first pump and thermostat. Cambelt changed twice but not the pump. Had a cool sensor replaced in 2012 aswell. So shall I run it up to temp and see if water goes through the bottl. Last time I ran it up in also found the top hose to the rad was hot, the bottom hose was cold and the rad it's self was cold so I clearly got a circulation problem.

Blimey, how long has the pump been on!

12 years. How long do they usually last?

4 years!

I'll be amazed if there's any blades left on that, new belts would extra strain on parts already getting brittle, and it's had 2 belts? Jeepers creepers. At my last change you could just snap the blades off, a new belt would have ripped it to pieces.

So it's been running on borrowed time lol. Might just jump straight in and get the pump and belt changed.

Borrowed time is an understatement lol, get a pic of it when you get it out, be nice to see what a 12 year old pump looks like.

Had my cambelt & water pump changed recently. Had a tick in the service book for a cambelt change at 60k in 2010 but the belt looked quite bad when it was removed. The water pump and belt were both genuine VAG ones so quite possibly both originals - car is 12.5 years old and is now on 124k. Water pump was all in tact but I think had slight play.

 

OP: if you plan on keeping the car then I would get the belt kit, water pump and thermostat replaced all in one go.

Yh I think I will. Anyone got part numbers for all what I would need so I can order it from tPs?

part numbers should be in the sticky http://www.briskoda.net/forums/topic/51616-octavia-useful-part-numbers-for-octavia-diy-servicing-and-mods/

What parts are actually needed?

Cambelt kit water pump thermostat?

Read somewhere about engine mount bolts too as they are stretch bolts?

Got a part number for the thermostat but can't see the other. Might start a new thread

what model and year car do you have?  that would help with identifying the parts

 

Alternatively you should be able to find most of the parts by entering your reg number on http://www.eurocarparts.com/

Edited 11 March, 201511 yr by mikec

2003 vrs. I'm after genuine parts so don't want to use ecp this time.

Genuine thermostats are a bit of a rip off considering they are basically the same for every car - just different fitments. I bought a Gates one for less than 1/3 of the price of an OEM one.

 

Same goes for timing belts, brakes and clutch kits.

 

My belt was replaced by an Audi tech of 10+ years and he didn't replace the engine mount bolts, but did say it was important to torque them up correctly.

Genuine thermostats are a bit of a rip off considering they are basically the same for every car - just different fitments. I bought a Gates one for less than 1/3 of the price of an OEM one.

Same goes for timing belts, brakes and clutch kits.

My belt was replaced by an Audi tech of 10+ years and he didn't replace the engine mount bolts, but did say it was important to torque them up correctly.

Did you use gates for the timing belt kit too?

Does the hydraulic tensioner need replacing too? Been quoted £80 for a genuine one from ebay as long as I buy the cambelt kit off them to. Seems expensive to me though?

Seen this kit here.

http://www.awesomegti.com/ecs-tuning-ultimate-timing-belt-kit-1-8t-150-180-225

Anyone used it