BMW M44B19 Thermostat & Water Pump Guide | E36 Compact 318ti 318is Cooling System Service | 005

Описание: BMW M44B19 Thermostat & Water Pump Guide | E36 Compact 318ti 318is Cooling System Service | 005

The BMW E36 318ti Compact that I bought on a whim needed a cooling system refresh to it's M44B19 engine. 20 plus year old BMWs are known for having cooling problems. Mostly because of neglect, age and the use of plastic.

Here are the parts that I used:
Red Coolant: https://ebay.us/hpyLKh
Thermostat: https://ebay.us/daRxv7
Water Pump: https://ebay.us/IDoXNl
Aux Belt: https://ebay.us/DcKM3e

I fully intended to replace the thermostat and the water pump, along with any hoses that looked like they needed it. But the car upped the ante by developing a leak. I first noticed it when the heater stopped working, which led to me checking the coolant level. Unfortunately there was no level to check, it was virtually empty, fortunately I saw this before any real damage was caused. The one thing that was certain, was that the car couldn’t be driven far until the work was done.

Besides the coolant leak there was a cacophony of impending mechanical disaster from the front of the engine. I felt it was quite likely it might be the tensioner pulley, or the water pump. To test this theory we ran the engine with the belts off and the noise stopped. This was a bit of a relief because I was worried that the noise might have been the timing chain or tensioners, but it turned out it was definitely the water pump.

Before removing the belts, we did look to see if we could find where the antifreeze coolant was coming out. Using a tissue to see if you could spot the leak. Surprisingly we found a smoking gun. You could actually see the coolant being sprayed around the engine bay as it was flicked by the water pump pulley. It was obvious that it must be coming from the thermostat. This wasn’t a big surprise as the thermostat housing for a BMW 318ti Compact is made of plastic and is reviled for cracking. By the way, this how-to guide also applies for BMW E36 318is which is also equipped with the M44 engine.

Having checked that the strange rattle noises were from either the water pump or tensioner by running the engine with the belts off, and listening, we removed the thermostat. When removed it was obvious that it was well past its best, with the plastic tangs that actually hold the metal part of the thermostat having completely broken off. There was also a lot of evidence that there had been a leak from around the thermostat.

We then got onto the water pump. Unfortunately one of the threaded lugs that are provided to get it off snapped off. Using heat and a big hammer we eventually managed to dislodge it from its home. It was a struggle but we did succeed in the end. It does seem to be a thing with these water pumps, we had a similar problem with the last one that we did on the BMW E30 316i which has the M40 engine, but a very similar pump to the M44B19 one.

We used the correct type of coolant when we refilled the radiator. We had a bit of a scare when we thought we had a leak, but it was only coming from the bleeder port, so it looked a lot worse than it was.

Once we had the coolant up to temperature the heater worked showing that the heater matrix had coolant going through it. The heater can be a source of air locks when refilling cooling systems, but this one worked out fine.

It makes sense to check the system a few times over the first couple of weeks after this type of work. You are looking for leaks by either the level going down or the appearance of wet patches on the undertrays. I found that the level remained constant, and as an added bonus the colour of the coolant stayed the same. Sometimes when you flush a cooling system you don’t manage to get all of the old coolant out, so the colour changes. If this happens you need to empty and refill the system to make sure you have a complete fresh fill, luckily this wasn’t a problem for us and we can leave it alone.

For more helpful how-to guides and restoration project logs, visit our blog: https://www.spannerrash.com/

As an Amazon Associate, Ebay Partner and Awin Affiliate, we earn a small commission from qualifying purchases. Some of our links are affiliate links, and if you decide to purchase things through them, we earn a small commission. It costs you nothing but helps us to keep the content coming. Thanks for your support!