[straightcashhomie]

In an interesting dilemma right now. I get mixed replies from who ever I ask this question. The car is sitting at 76xxx miles right now. Should I preemptively change out my water pump and thermostat?

My OFHG and VCG are leaking. So I will be replacing those 2 gaskets plus the oil filter cooler gasket, as well as doing all of my fluids. A lot of people tell me, if the water pump aint broke, don't fix it (ahead of time). Kind of nervous to see oil in the coolant reservoir. There has to be bits of the gasket circulating through which may cause the WP/Tstat to fail sooner than later. Thoughts?

[catcher22]

Fix your gaskets, do an oil change and coolant flush, and drive it until your pump goes out. Then replace your pump and tstat together.

No need to replace the pump as preventative maintenance unless you frequently take long trips. Once the pump dies, it'll leave you stranded give or take 1/2 mile. Some people replace it early because they don't want to be stranded.

Mine left me stranded on a beautiful saturday evening just 3 miles from my house. really was not a big deal at all.

[dyezak]

It is always cheaper to fix things you know will break before they actually break...because you can do it on your schedule, with non emergent labor, by purchasing parts at leisure from the most economical resource.

[Jklad]

Like the guy above said, if you don't care about getting stranded then you can try to ride it out and take your chances.

Personally I would replace now to avoid being stranded.

[ucdbiendog]

I doubt there will be bits of gasket floating around in your coolant. you'll be able to tell positively when you take them off if the gaskets are whole.

[arhoads335i]

It's known that parts of the oil filter housing gasket get in the coolant and eventually take out the water pump so yeah do the gasket and flush the system

[Bent_remy]

Originally Posted by dyezak

It is always cheaper to fix things you know will break before they actually break...because you can do it on your schedule, with non emergent labor, by purchasing parts at leisure from the most economical resource.

What he said. I waited and the waterpump went out a miles from home leaving me stranded with a long walk of shame. Now that I know these cars self destruct at 70K miles I would have definitely changed it earlier.

[jwebb335xi]

Originally Posted by Jklad

Like the guy above said, if you don't care about getting stranded then you can try to ride it out and take your chances.

Personally I would replace now to avoid being stranded.

I had intended to replace mine, but was out picking up lunch when it failed. I left the car with my Indy and my wife picked me up. No real harm, but I paid for an install that had I planned for I could have done. If you keep the car, you'll replace water pump and t-stat. Do it under your terms.

By the way, when doing OFHF, you may want to plan for top radiator over flow hose AND the smaller hose just beneath the OFH; that one broke when I was doing my OFHG, which I understand is common. Having all the parts available would have saved me a trip to the dealer in the middle of the work!

Also, when doing the water pump and t-stat, it's a really good time to replace all the hoses connected there. They will cost an extra $150 MAYBE..

[Jeff@TopGearSolutions]

If you are ok with being stranded or towed when it fails then wait, otherwise preemptively replace.

[coochmon]

For those thinking about water pumps and OFHG leaks: DO IT NOW. Seriously.... My OFHG was seeping a VERY tiny amount externally... then disaster. 2 days ago my low oil light came on while sitting in traffic in a rain storm. My car never burns oil and only time it was low on oil was when the stud on the pan rusted off where oil level sensor is mounted (130k N52 2007 328i). I take a look this time - and over a quart of oil went into my coolant system - and that was too much volume so it blew oily coolant out of the expansion tank. What a mess. This OFH gasket was only about 60k old. It was a nightmare because the OFH bolt head under the manifold got munged - I had to pull the intake manifold to get a straight shot and extract - also purging the cooling system of all oil is a HUGE pain. Also, my last waterpump lasted only 53k (BMW branded!). I replaced with Pierburg OEM. You will always snap off the little fittings and the upper radiator hose doing this by the way, so have one on hand. Just a little friendly advice, pictures below...look at that gasket! And that bucket of yuck is my antifreeze drained.

[Sgop335]

Originally Posted by coochmon

For those thinking about water pumps and OFHG leaks: DO IT NOW. Seriously.... My OFHG was seeping a VERY tiny amount externally... then disaster. 2 days ago my low oil light came on while sitting in traffic in a rain storm. My car never burns oil and only time it was low on oil was when the stud on the pan rusted off where oil level sensor is mounted (130k N52 2007 328i). I take a look this time - and over a quart of oil went into my coolant system - and that was too much volume so it blew oily coolant out of the expansion tank. What a mess. This OFH gasket was only about 60k old. It was a nightmare because the OFH bolt head under the manifold got munged - I had to pull the intake manifold to get a straight shot and extract - also purging the cooling system of all oil is a HUGE pain. Also, my last waterpump lasted only 53k (BMW branded!). I replaced with Pierburg OEM. You will always snap off the little fittings and the upper radiator hose doing this by the way, so have one on hand. Just a little friendly advice, pictures below...look at that gasket! And that bucket of yuck is my antifreeze drained.

Summer 2023, road trip...my 535i did the same. some interesting differences, it was not seeping externally and coolant tank blew (burst)...

So the 5 series have a 200kPa coolant cap instead of the 140kPa on the 335...so that didnt help the coolant tank...

OFHG was probably chgd by previous owner and I chalked it out to a low grade gasket...very critical component.

The mess...also had a bucket like yours. In my case, i think may be 4 ltrs oil leaked to the coolant.