Alfa Romeo Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I've recently replaced the thermostat on my 156 2.0 jts, all good for a while but now there's coolant leaking out from around the water pump area. I hadn't noticed anything until last night when driving the car the temp gage went up over 3/4s the way, when I checked coolant level it was empty so put some water in it last night just to cool it down a bit & left it to look at until this morning. So this morning I discovered it was completely empty of coolant. After topping it up half & half I noticed it leaking quite heavy around the water pump area. I've slipped a disc I think & because of this I can not properly check it out but I'm thinking water pump. My partner needs the car to get to work so I've put a bottle of K-Seal in the system but it's just slowed it up a bit. When I drove it today after doing this the temp gage quickly went up to 3/4s the way again but I noticed the heater was blowing out cold air when set on max heat. Has anyone got any idea what is going on with it?

Sent from my SM-T585 using Tapatalk
 

·
Registered
Joined
·
2,393 Posts
There's not really much by way of good news here. It seems like the coolant pump is leaking and this needs to be addressed. I'd guess that the leak is the bearing seal rather than the casing O-ring seal. That being the case, it's either a defective/worn seal or defective/worn coolant pump bearings. The coolant loss suggests it needs sorting without delay.

In the 156, Twinspark and JTS cooling systems have no coolant bleeding points. It is not so simple/easy to purge air from cooling system. I find the best way to do this is to raise engine speed to at least 5000rpm for about 10 seconds when the engine is partially warm. Obviously, do not do this if coolant pump bearings are suspect.

That is the problem. You cannot do that without risking catastrophic engine damage until you know the cam belt driven coolant pump bearings are good.

The short answer is cam belt and coolant pump must be checked and likely changed ASAP. If money is tight, you could leave the belt off the balance shafts and not replace that and tensioner as necessary. I'd recommend changing the auxilliary drive belt if necessary, too.

As a side note, due to very short cam belt life, it is unusual to find coolant pump failure. The pump should be changed every belt change or possibly every 2nd belt change if annual mileage is high (say 20k or more per annum). Recommended cam belt interval is every 36k miles/60k km or 3 years since it was reduced from 60k miles or 5 years (about 14 years ago when Alfa Romeo released an amended service schedule bulletin).
 

·
Registered
Joined
·
2,393 Posts
The overheating/erratic gauge reading/lack of warm air in heater is consistent with low coolant level and/or failure to purge air from coolant system.

Looks like this has come at a very bad time for you. That is most unfortunate and I hope this can be resolved quickly and not too expensively. Continuing to use the car risks overheating damage though.:disappointed:
 

·
Registered
Joined
·
9,149 Posts
As a side note, due to very short cam belt life, it is unusual to find coolant pump failure. The pump should be changed every belt change or possibly every 2nd belt change if annual mileage is high (say 20k or more per annum). Recommended cam belt interval is every 36k miles/60k km or 3 years since it was reduced from 60k miles or 5 years (about 14 years ago when Alfa Romeo released an amended service schedule bulletin).
It depends on the pump manufacturer too. I had one fail after 15k miles (About 18 months use) .. that was not a happy moment.

It was fitted by a "specialist" during a regular cam belt change but outside their "12 month" parts guarantee period. It was definitely the seal once it was off. No idea of the make/brand. The original pump lasted over 73k miles!!

All subsequent pumps (I did the cambelts) lasted the 36K. And they would probably have been fine for longer .. but once bitten, twice shy! ... so were replaced.
 

·
Registered
Joined
·
2,393 Posts
It depends on the pump manufacturer too. I had one fail after 15k miles (About 18 months use) .. that was not a happy moment....

...It was definitely the seal once it was off...
I really don't intend to be churlish but which seal?
Failure of casing outer seal is usually due to damage during fitting.

I've let pumps go to over 100k (TS only) not had one fail. However, going on others' experience, I've been lucky. No more than every second belt change now.

Quitting whilst I'm ahead is a skill I'm paying more attention to develop as I get older.
 

·
Registered
Joined
·
9,149 Posts
I really don't intend to be churlish but which seal?
Internal seal on the pump drive shaft. Could have been a dodgy seal or batch or just a cheapo pump that specialist picked up to save him ££s. (Same one used NTK lambda sensors which are wrong ohm rating for 156 .. only Bosch are correct)

Blue Hylomar to seal pump body to block!
 
1 - 6 of 6 Posts
Top