Options once oil is in coolant

**PerthDisco** · 31st December 2020, 02:30 PM

Yesterday I pulled apart my super non mechanical brother’s E30 325i beloved BMW fun car as it was overheating and ‘not right’. In draining coolant it was more a viscous chocolate smoothy concoction so proceeded to take off the head.

Head seems fine with no detectable cracks.

Every coolant hose was full of this smoothy and the valve camshafts and valve cover coated in same. Got head off and the block galleries full of same mixture. Took water pump off and let the block drain of this goo out the front.

Drained sump and removed oil filter with more cross contamination.

So now assessing options for the slow rebuild;

Head can go to a rebuilder for checking and rebuild.
Radiator- can it be flushed?
Hoses scraped and replaced.
New water pump and thermostat housing.
New seals and gaskets etc.
New timing belt kit.

My question is without removing the headless engine and doing a full rebuild what’s the best way to clean the coolant side of the block to remove the slimy goo? Steam cleaner or lots of degreaser and hose out?

What about sump side? Probably should drop the sump.

Same for heater hose circuit any tricks to flush the heater core? Hot soapy water run through?

Anyone with BMW experience can point me to a good online parts supplier for these 80’s vintage models.

Super easy to work on and access things.

Thanks.

**Bulletman** · 31st December 2020, 03:13 PM

Believe it or not , we have had oil coolers fail on several occasions in the 3306 cat gensets and the 3412.. V12 cat main propulsion engines in our fishing boats and we use Finish dishwashing powder to flush the cooling systems.
Done it more than a dozen times and never had an oring or gasket leak or fail during or after the process. Just add the powder to the cooling system and start the engine up and let it run for 30 mins or so and drop the cooling system. refill and you will be lucky to see a trace of the oily goo.

In your case seeing as you have removed the head, you may be able to mix some in a 20ltr drum and use a drum pump or some similar type of set up.

hope this helps

Bulletman

**DeanoH** · 31st December 2020, 05:21 PM

Are you sure it's oil and not ATF ? Does the BMW use a 'heat exchanger' cooler in the radiator ?

Deano

**PerthDisco** · 31st December 2020, 08:12 PM

Originally Posted by DeanoH

Are you sure it's oil and not ATF ? Does the BMW use a 'heat exchanger' cooler in the radiator ?

Deano

It’s a manual in any case. Radiator has only top and bottom hoses.

**PhilipA** · 31st December 2020, 08:18 PM

You are lucky it is old enough not to have Vanos.
Regards PhilipA

**PerthDisco** · 13th January 2021, 06:02 PM

Ok so everything is pulled apart and gone to the wash bucket to get the mayonnaise coolant out of it. Head off to reconditioners, the block is washed out and the sump I’ve removed to thoroughly clean out and replace the leaky gasket.

So now preparing for the rebuild on this 89 era engine that uses paper gaskets throughout. The engine was known for many common oil leak locations.

So have given myself a quick education on Gasket Makers (RTV) vs Gasket Sealants and learnt you only want to use the latter to dress a gasket and never the former which is designed for gasket-less joins.

So not withstanding immaculate surface prep just wondering what sealant product any regular rebuilders of old engines are using to help the gaskets achieve a long lasting leak free engine? Noting, nothing gets added to the head gasket.

**DoubleChevron** · 13th January 2021, 06:33 PM

Originally Posted by PerthDisco

Ok so everything is pulled apart and gone to the wash bucket to get the mayonnaise coolant out of it. Head off to reconditioners, the block is washed out and the sump I’ve removed to thoroughly clean out and replace the leaky gasket.

So now preparing for the rebuild on this 89 era engine that uses paper gaskets throughout. The engine was known for many common oil leak locations.

So have given myself a quick education on Gasket Makers (RTV) vs Gasket Sealants and learnt you only want to use the latter to dress a gasket and never the former which is designed for gasket-less joins.

So not withstanding immaculate surface prep just wondering what sealant product any regular rebuilders of old engines are using to help the gaskets achieve a long lasting leak free engine? Noting, nothing gets added to the head gasket.

Does it have liner seals ? or paper gaskets at the bottom of the liners that set the protrusion height

**PerthDisco** · 13th January 2021, 06:45 PM

Originally Posted by DoubleChevron

Does it have liner seals ? or paper gaskets at the bottom of the liners that set the protrusion height

It’s an iron block / ali head with no separate liners that I know of or have read about on this M20 engine.

The main paper type seals are sump, lower timing cover, water pump, thermostat housing with orings looking after most other oil / water leak locations. Seperate to this is gaskets on the inlet manifold between throttle body and other vacuum line take offs.

Top of block is level with a composite head gasket

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