Hi all,

Big issue with my car on the way home tonight, had the engine temp increase when going up a hill close to home, I have a nasty feeling that the water pump has failed somehow, here are my symptoms:

• Engine temp high but does reduce when idling
• Radiator cool
• Expansion tank pressurized
• Heaters COLD
• No movement of fluid in the expansion tank when engine is on
• Coolant in top hose of rad
• No loss of coolant

 

I initially thought it was a stuck thermostat but that would mean that the heater core would be hot which it isn't, the thermostat itself is hot but I have a feeling that its the water pump that has gone as there isn't any flow in the expansion tank. I know when I did change over the thermostat I did see coolant circulating and swirling within the expansion tank when refilling, this isn't the case anymore.

The waterpump was changed with the cambelt around 30k miles ago, the engine itself runs fine meaning that the cambelt itself is ok, I am therefore guessing that the waterpump has failed internally as there isn't a loss of coolant, its just not flowing around. I think the smoking gun is the fact that the heater is cold even with the engine running and after a drive, I did also 'pump' the top rad hose which then did move fluid around the system a bit, this did then give me a tiny bit of hot heater but then went cold soon after.

Anyone else think its the water pump? It might be a MASSIVE air lock somewhere in the system but when I pulled the top rad hose off the thermostat there was plenty of coolant flowing out of it.

I have a feeling that I might need a new car as the cost to replace the water pump might not be worth it considering its attached to the cambelt etc.

What engine do you have?

sounds like it could be the waterpump. 

35 minutes ago, stef123 said:

What engine do you have?

sounds like it could be the waterpump. 

1.4 TDCi, its been flawless for a while, it did have a leaking thermostat which I then swapped out, it was fine on the motorway home, only failed when accelerating up a hill on a bypass home. If the heaters were burning hot I would guess thermostat, however they are cold meaning no water flow, I will check tomorrow when its 100% cold to see if its taken water from the expansion tank. I could technically get away with running an booster electric water pump but not sure what best to do now owing to the high cost of swapping the pump out etc.

Did you fit the timing belt/pump yourself? What brand of replacement parts did you use?

53 minutes ago, stef123 said:

Did you fit the timing belt/pump yourself? What brand of replacement parts did you use?

It was changed at a garage at 91k miles as soon as I bought the car along with the cambelt, followers etc its all brand new, I think I bought a Dayco all in one kit which had everything.

According to the data I have in front of me its a 3 hour job to replace pump and belt kit, to be honest looks like you may need to have it done again unless your handy with the spanners. 

1 hour ago, stef123 said:

According to the data I have in front of me its a 3 hour job to replace pump and belt kit, to be honest looks like you may need to have it done again unless your handy with the spanners. 

I found the receipt for the cambelt change from my local garage, it came to £115 for labour plus some antifreeze, I supplied the parts - so should be less than £200 all in I recon, more of an issue is that I need the car to get to work as I can't get the train there (70 miles round trip). Basically the worst timing but at least it went before the long drive I did have planned on Christmas, also means that I can get the cambelt done again for the engine to last even longer - its on about 30k miles at the moment.

 

I am going to try and bleed the coolant system tomorrow as well, I think I also have the old coolant temp sensor as well which I know works correctly, just in case its something like a sensor issue, might also pull off the thermostat to check, just typical no garages are open for the next few weeks!

Just a quick update on this, it was the water pump as expected, the impeller shattered at around 25k miles of motorway driving meaning that the cambelt was fine but there just wasn't anything connected to the other side! I have had the pump replaced along with the cambelt at the same time and its all running as it should - returning low 70 mpg on the trip computer on the way into work this morning.

Just a note on how to spot if the pump has failed, when the engine is cold open the expansion tank and then start the engine, if you see water circulating in the expansion tank its not the water pump. With my issue I found that the thermostat side of the engine was hot/warm and could manually pump water by squeezing the top rad hose (also warm meaning the thermostat was fine) but the pipes from the water pump were cold. Also the heater was completely cold but I could get some heat for a few seconds after manually pumping the top rad hose. Also pump the bottom rad hose to check that the radiator itself isn't blocked - pumping both top or bottom rad hoses should result in movement in the expansion tank.