Project 35: Water Pump & Thermostat Replacement

[Wayne 962]

Got any questions on Project 35 for your E36 or E30? Ask them here!

-Wayne

[GeeEss11SqdHntr]

Wayne ~
How long should it take to change out a thermostat and water pump on a '94 325 is (e36) ? Been running hot for a week or so, figured I tackle both instead of doing just the thermostat.

[Matt at Dunlop]

It is that time of year, isn't it?? When everyone starts to slowly realize their car isn't getting up to operating temp very quickly, if at all, as the weather gets colder...

Anyway -- I replaced my t-stat (which was stuck open), water pump, both belts, new coolant, new oil, and new MTF last weekend. This was my first time wrenching on my '95 318is (M42 motor).

It took me about 2.5 hours to disassemble everything (plus oil & MTF change), and about 2 hours to button it back up and fill/bleed the coolant and clean everything up.

It's worth mentioning that I purchased the fan counter-holder tool from pelican parts -- it made removal of the radiator fan a snap.

Hope this helps,
Matt

[Wayne 962]

Yes, you can struggle for hours without that fan tool - it really is a must. I tried one day when I forgot it at work - no go.

As for the entire job, if you haven't worked on the car before, I would allocate an afternoon for it. If you have, then a few hours. In general, these are pretty easy to get to and replace...

-Wayne

[rotophonic]

I'm in the process of replacing the water pump, thermostat and thermostat housing, but I've hit a bit of a snag.

The old thermostat is gummed up and won't come out of the engine block. I removed the old o-ring from around the edge of it, but it won't budge. I tried using a screwdriver to pry it out using the loop of metal on the top of the therm, but that loop of metal just broke rather than loosening the thermostat.

Are there any hints on how to loosen this? Perhaps some spray or liquid I could spray around the edge to dissolve some of the crusty buildup? I'm sure water would work slowly, but I'd love something more rapid. Perhaps Lime-Away?

Thanks for your help!

Robert

[Dub-Dub]

The problem i ran into last time... in addition to not having the thin wrenches of the fan (really get it), was rotating the engine in an automatic... i don't recall how i solved it, but man was it a PITA until I did. I am looking forward to my second belt changing in the spring.

[rotophonic]

This is solved now. I ended up using CLR and a brush, scrubbing around the outside many times. It probably took around 90 minutes until a good pry of the screwdriver popped the thermostat out.

Good thing I swapped out the plastic thermostat housing for the aluminum version. The inner plastic lip holding the rubber gasket had broken off in two places.

Thanks, Wayne, for a great book and good detail for the newbie wrenchers like me!

Robert

Originally posted by rotophonic
I'm in the process of replacing the water pump, thermostat and thermostat housing, but I've hit a bit of a snag.

The old thermostat is gummed up and won't come out of the engine block. I removed the old o-ring from around the edge of it, but it won't budge. I tried using a screwdriver to pry it out using the loop of metal on the top of the therm, but that loop of metal just broke rather than loosening the thermostat.

Are there any hints on how to loosen this? Perhaps some spray or liquid I could spray around the edge to dissolve some of the crusty buildup? I'm sure water would work slowly, but I'd love something more rapid. Perhaps Lime-Away?

Thanks for your help!

Robert

[grauster]

Hi Wayne, et. al.,

I just tackled my first DIY yesterday on my '99 323is, swapping out the water pump, t-stat % housing, and coolant change. Your book made it really straighforward to someone who has never really worked on cars, but wants to learn...I thank you.

So everything went perfect except for one thing...when going to torque the nuts back on securing the water pump, the lower right stud snapped off.

So now I've got 3 out of 4 of the nuts tightened to spec. Everything seems to be running smoothly and I haven't noticed any leaks, do you think this is something to really be cornered about? If it is, what type of labor does getting than bolt out without removing the timing case, vs. removing the timing case entail? What do you think a shop would charge / how many hours of labor?

It really seems to be on there pretty good with the 3 nuts secured, should I wait to address this until I notice leakage?

Any advice would be greatly appreciated, thanks in advance.

[Jeron]

I doubt it will fail catastrophically so leaving it and watching for leaks is an option. Thats is, unless the stud failed for a good reason and the same reason afflicts the other studs.

[grauster]

Yeah I mistakenly over-torqued it and the stud snapped from within the timing case. Pretty dumb, I'm just trying to muster enough confidence to feel ok with leaving it in with 3 of the nuts. I couldn't even budge it with the 3 nuts tightened...I am just cringing at the thought of having to take it in to have everything dismantled so that a new stud can be threaded into the timing case...that far exceeds anything I would even attempt. Thanks for you thoughts...more are welcome.

[stupenal]

I also ran into the stuck t-stat. Ended up just grabbing a pair of pliers and yanking the darn thing out. There's a part that protrudes out the rear of the t-stat - grab it with a pair of pliers and it should pull out.

[elsabor67]

Wayne,

I have a question about the E30 water pump on a 89 325i.. If the pump fails for any reason, would there be anything audible or would no water going thru the lower hose or bleeder valve be an indication? I have the 101 projects book and it really didn't have alot for the E30 water pump and when I went to the site there wasn't much there either for the E30 water pump.

Any help would be really appreciated. Great book btw. It helped me alot on some other matters.

Nick

[Jeron]

Expect no cabin heat, no lower hose heat, quickly overheating the engine.

[elsabor67]

Originally Posted by Jeron

Expect no cabin heat, no lower hose heat, quickly overheating the engine.

So I checked the water pump today and IT DOES WORK!!!!

As you said, there was no cabin heat and the car does get hot pretty quick. Could the head gasket be done for? It was replaced less than a year ago and I don't have the "Chocolate Milkshake" syndrome in my oil pan. Coudl the head gasket block the water jackets for any reason?? Any advice woudl really help.

Thanks again and thanks for the earlier response.

Nick

[scoflaw45]

Hello all. I was about to r&r a busted belt yesterday and I happened to give the water pump pulley a turn.....Hmmmph! Froze up.
I ordered a new pump from NAPA - I'm checking my 101 P. projects waterpump dept. and found notice of this site... What a lifesaver! But I suppose everyone already knows that.
So, the fan clutch seems faulty too....irregular tension when revolved. I'm thinkin' I'll replace the pump and try to get home(about thirty miles) without a fan. I live in Alaska and the average daytime temp. is avg.22F. Will I make it? Am I missing something? If it gets too warm I can always stop for a few minutes. It's Cold out.... Thanks, Dave

[Jeron]

You will not need a fan to drive in 22F temps. Watch the gauge to be on the safe side. As long as your secondary fan works you can probably drive year round in AK without a primary fan but I would not recommend it.

Your biggest issue will probably be getting all the air out of the system. It seems to foil everyone.

[Jeron]

Originally Posted by elsabor67

So I checked the water pump today and IT DOES WORK!!!!

As you said, there was no cabin heat and the car does get hot pretty quick. Could the head gasket be done for? It was replaced less than a year ago and I don't have the "Chocolate Milkshake" syndrome in my oil pan. Coudl the head gasket block the water jackets for any reason?? Any advice woudl really help.

Thanks again and thanks for the earlier response.

Nick

The engine should get hot quickly, but not go past 12oclock.

If the head gasket is blown you should see sings in the oil or the coolant.

The most common cause of no cabin heat is air in the system.

[gldfshkpr]

The book says Pelican sells a radiator kit. Can't find it on the site. I have a 97 318i and need to replace the radiator. Is there a kit with all the parts for that job?

[Jeron]

I dont know if they have a kit or not, but you can call/email them and they will help you decide what parts you want to replace.

There arent any other required items to replace with the radiator but there is an endless list of thing you might want to replace while you're there.

I would get at least one of the two radiator top clips because they are hard to release if you have never done it before and you will probably crack the first one. 17-11-1-723-341 I'd also get a metal thermostat housing, gasket, thermostat and expansion tank. Main Hoses, belts.

Check:
your tensioner pulley bearings
the plastic fan for cracks
check the operation of the fan clutch with a newspaper with the enigne running

[gldfshkpr]

Originally Posted by Jeron

I dont know if they have a kit or not, but you can call/email them and they will help you decide what parts you want to replace.

There arent any other required items to replace with the radiator but there is an endless list of thing you might want to replace while you're there.

I would get at least one of the two radiator top clips because they are hard to release if you have never done it before and you will probably crack the first one. 17-11-1-723-341 I'd also get a metal thermostat housing, gasket, thermostat and expansion tank. Main Hoses, belts.

Check:
your tensioner pulley bearings
the plastic fan for cracks
check the operation of the fan clutch with a newspaper with the enigne running

Okay, thanks Jeron.