8 replies to this topic

[dan1zo]

Hey fellow enthusiats.

Ive been having issues with my 98 mpi overheating for the last 12 months. It started sporadically but now i need to do something about it now i have the time.

Today i changed the oil, it hadn't been done for ages. Was black and gross. Put in 20w50.
Ive also had the radiator out and checked for leaks, cleaned it out. Flushed the coolant. Checked the water pump and all seems ok.
Today something bad seemed to happen. I ran it up to temperature and all seemed ok to begin with. Fan came on as expected but i went to check in the engine and i could tell the water was boiling. And saw water leaking.

What i though was water spraying from the radiator was in fact spraying from the engine block. Have a look at the picture.
How serious is this? Something blocked in the coolant flow in the block?

Are we looking engine out or is it dead?

Attached Files

•  IMG20260502152121.jpg   61.7K   9 downloads

[primrose8]

That’s a core plug it’s leaking from, not too serious probably corroded, you can buy the core plugs and replace it in situ

[dan1zo]

That’s a core plug it’s leaking from, not too serious probably corroded, you can buy the core plugs and replace it in situ

Ok well thats good at least. But with the overheating, is it likely that the waterways are blocked and preventing proper coolant flow? I guess that would need more investigation?

[sonscar]

When you remove the core plugs you can access some of the waterways and poke them cleaner.Steve..

[lsto]

If one core plug has failed then change all of them whilst your there, I did mine recently because one was leaking and they were all in poor condition. If you have an overheating problem then first things first check the coolant level, obviously you already found a leak. Next change the thermostat, they are cheap and easy to change.

[Wiggy]

What is the temperature gauge doing?

Side note: I'd pull the heater core & flush that out of the car. Mine was a absolutely chock full so I replaced it. The hot / cold valve in the car gets stiff if it's full.

[pete l]

With a water leak, you won't be getting the system under pressure, so it will boil.

[dan1zo]

Hey guys thanks for the feedback. Im getting that core plug sorted. It was overheating before that though. So ive also checked the expansion tank cap and replaced that too. Could be that was stuck open. I didn't realise it was so sensitive to pressure change.
Heater matrix is definitely clear. I don't have the standard heater unit anymore.

[dan1zo]

What is the temperature gauge doing?

Side note: I'd pull the heater core & flush that out of the car. Mine was a absolutely chock full so I replaced it. The hot / cold valve in the car gets stiff if it's full.

It was getting up to normal mid temperature and fan was kicking in as usual. Then after a while it would just shoot up to the red. 

Im guessing it is a pressure issue. So once the core plug is sorted, hopefully is ok and it was the expansion cap.