Engine overheating and rusty water pump

[chacha]

I have replaced a water pump and radiator but engine is still overheating.
Old water pump impeller was very rusty. Removed engine block drain screw at the rear of the engine but water is not coming out.
Any suggestions on next steps? Thanks!

 

[André4Renaults]

You could try reverse flushing the block, by connecting a hose pipe to the drain screw and pushing water through backwards. Some pressure from the hose might help, too. Another option would be adding some bicarbonate of soda , which might help shift any debris that's stuck inside the block.

I've a few other more drastic suggestions, but you'd be advised to try the more gentle methods first!

 

[Andy McGhee]

Sometimes there's a build-up of rust and debris immediately behind the drain plug. If you use a bent bicycle spoke very carefully, you should be able to remove it.

 

[chacha]

Sometimes there's a build-up of rust and debris immediately behind the drain plug. If you use a bent bicycle spoke very carefully, you should be able to remove it.

poking bent wire in did not yield any results I fear engine coolant channels might be blocked by rust. Really want to avoid taking cylinder head off if at all possible.

 

[JdeW]

poking bent wire in did not yield any results I fear engine coolant channels might be blocked by rust. Really want to avoid taking cylinder head off if at all possible.

Taking the cylinder head off is your only solution to clean everything by the looks of rust inside your waterpump.
Make sure to secure the cylinder liners after removing the head.

Here you see a typical build up of rock hard debris at cylinder 4 were the rear drain plug resides (I did a full engine overhaul so the liner is removed)


So roll up your sleeves and get started. There's plenty of knowledge and examples of restoring and cleaning parts on this forum, and don't hesitate to ask.

 

[André4Renaults]

Taking the cylinder head off is your only solution to clean everything by the looks of rust inside your waterpump.
Make sure to secure the cylinder liners after removing the head.
View attachment 35935
Here you see a typical build up of rock hard debris at cylinder 4 were the rear drain plug resides (I did a full engine overhaul so the liner is removed)
View attachment 35934

So roll up your sleeves and get started. There's plenty of knowledge and examples of restoring and cleaning parts on this forum, and don't hesitate to ask.

This was the "drastic" action to which I alluded..... Yup, if you can't shift the detritus by flushing then it looks like it's a "heads off" job. The advice included in the above post regarding securing the liners in place is vital and I'd recommend a careful reading of everything before commencing.... Good luck!

 

[chacha]

I was hoping to get the car drive-able this month but cylinder head off will delay things until Christmas.

 

[malcolm]

Just a thought - have you properly bled the coolant system? Hold expansion bottle above engine, open heater bleed, squeeze pipes to rad to move air, mske sure radiator is full.