10 year old timing belt

[khiobrien2]

I recently bought a 1986 325es with 130,000 miles. Previous owner had maintained it very well and dumped over 10k into it... other than one thing. The timing belt has not been replaced since 2013/2014 but has just over 25k miles on it. He has multiple mechanics on record saying he is fine on that tb. Is this as urgent as forum posts ive read have made it sound? I understand the risk at hand. Is it really possible it is fine after all this time? PO drove it frequently but very little over 10 years of ownership. Is there really no way it is still healthy?

[rturbo 930]

It might be fine. But if it's not fine it's gonna be expensive. Change it.

It's an inexpensive thing to change. Rubber degrades, and might degrade faster or slower depending on conditions. At a minimum, you should at least take a look at it and see if it looks good, or if its cracking, but you should really change it. It's not that difficult. Also IIRC timing belt interval is 4 years or 60k miles, so it's well past the time interval and at about half the mileage interval.

[roguetoaster]

Could last ten years, or could fail on the next startup. It's up to you if you want to roll the dice.

[e30austin]

5 years/50k mile is the max interval, to me, for any M20 timing belt service. i don't give a shit what anyone says, rubber fails with time, particularly with lack of use and the belt sitting in the same position for weeks/months on end. it's cheap insurance to make sure the engine stays in good working order. why wouldn't you want to do it?

[khiobrien2]

5 years/50k mile is the max interval, to me, for any M20 timing belt service. i don't give a shit what anyone says, rubber fails with time, particularly with lack of use and the belt sitting in the same position for weeks/months on end. it's cheap insurance to make sure the engine stays in good working order. why wouldn't you want to do it?

Only reason I was debating delaying it is that I just did a coolant flush/bleed a week ago so it is unfortunate timing to drain it again.

[packratbimmer]

It is possible to change the belt without dumping the coolant, just a little trickier.

[e30austin]

nothing that says you can't reuse it, though, if you used green coolant, flush that garbage out and install blue G12 coolant. the green stuff is hard on bearings and promotes electrolysis.

[e30rik]

Change it for peace of mind if nothing else. I did my first tb job almost a year ago and it was really pretty straight forward even for a weekend wrencher like myself. The guy I bought the car from told me he just did it but that wasn’t good enough for me, would rather just know instead of hope. There’s a couple good videos of people doing the job step by step as well as write ups. Just go through some of those and make sure you have all the tools and ability.

[packratbimmer]

Only use BMW blue in an E30. It is possible to change the belt without changing water pumps, in other words. In addition, it COULD be better to use an old water pump (a high quality one, in functional condition) than to swap out a new one that is possibly a piece of junk. The last time I changed one, I went for OE due to such bad luck with aftermarket. BTW - there are also a lot of junk belt tensioners out there so do some research on those as well.

[uturn]

I just did my timing belt on my m20. Last change was about 10 years ago. Similar ~25k miles. Belt was fine, tensioner didn't have any lateral play but showing its age when you spin it. Easy job, you don't need to drain the coolant unless you used that green stuff- switch to the bmw blue.

Have a spare distributor rotor on hand as the three allen bolts usually fight you and get destroyed. Any seals you might want to change out and a water pump every other belt change. Same as packrat- I too had to go OE for my waterpump as I had gotten an aftermarket piece of junk.

I shouldn't have let my belt go so long but I've been busy. Going to try to be more diligent and target 6-8 year intervals from now on.

[TobyB]

I too would change it. And that reminds me to change mine, too- thanks!

As to green coolant: just like oil, everyone has their preference. I have found
for the last 40 years that the green that's rated for aluminum has worked ok
for me. IF changed every couple of years, like you should, anyway.

t
never used blue. Still here to tell you so!

[khiobrien2]

I just did my timing belt on my m20. Last change was about 10 years ago. Similar ~25k miles. Belt was fine, tensioner didn't have any lateral play but showing its age when you spin it. Easy job, you don't need to drain the coolant unless you used that green stuff- switch to the bmw blue.

Have a spare distributor rotor on hand as the three allen bolts usually fight you and get destroyed. Any seals you might want to change out and a water pump every other belt change. Same as packrat- I too had to go OE for my waterpump as I had gotten an aftermarket piece of junk.

I shouldn't have let my belt go so long but I've been busy. Going to try to be more diligent and target 6-8 year intervals from now on.

How is it possible to changed the belt without draining the coolant? Don’t the hoses need to be removed?

[82eye]

I too would change it. And that reminds me to change mine, too- thanks!

As to green coolant: just like oil, everyone has their preference. I have found
for the last 40 years that the green that's rated for aluminum has worked ok
for me. IF changed every couple of years, like you should, anyway.

t
never used blue. Still here to tell you so!

was the blue even available when these cars were new ?
all i know for sure is i'm using the blue on my refreshed engine. all the major aluminum hose connections were compromised. the thermostat housing was in very bad shape. had to replace them all.

[zaq123]

How is it possible to changed the belt without draining the coolant? Don’t the hoses need to be removed?

you are correct. You will need to take off hoses and the steel coolant line that's attached to the front of the block. I know this cars are not DD cars these days so TB change is mostly for the time vs mileage. However I would still do the tensioner and the water pump at the same time. I lost my beloved AHL TDI (golf) because I was late by ~2k to do TD belt on it. The belt broke because the water pump seized suddenly. I was on my way to the diesel mechanic for TB job, which made it even worse (emotionally).
When I called from the side of the road to cancel the appointment, VW diesel mechanic told me one thing I remember to this day : " When Germans tell you to change something at XX miles, it means XX mile, not XX plus 100 or 1000".

Water pump is not driven by TB on M20s but it's cheap enough to throw it in (while you are in there.

[digger]

I use genuine WP from stealership so do it every second TB.