help me decide how old this timing belt is (pic)

[2.5-12]

Hello all, I just bought another project car, its a 1990 E34 525i (I know this is an E30 forum) with a M20B25 and the Getrag 260.

the drivetrain seems tip top, makes a fair bit of valvetrain noise but they all do and this one was likely run on 30 weight oil like most neglected BMWs.

my question is: I was able to take a picture of the timing belt through the opening where there should be a plastic cap, how old/many miles do you guys think it has on it? looks pretty decent to me but I just have no idea. I would prefer not have to change 3 belts this spring.

[nando]

if you don't know, replace it. a kit is only like $35-$45. a used motor is going to be $500, and a lot more work.

[jlevie]

Unless you have proof of the age of the timing belt, replace it.

[2.5-12]

normally I'd agree but this belt shows no signs of cracking and very little wear. the parts may only be $40 but it takes quite a long time to do and I'd like to avoid frivolous tasks whenever possible.

again, I'm just asking how old people think it is, not if I should replace it or not

[nando]

It should only take an hour and a half. How long does a motor swap or head rebuild take?

Nobody is going to be able to tell you how old it is from looking at it, either.

[E30Gus]

Looks REALLY old!

[2.5-12]

It should only take an hour and a half. How long does a motor swap or head rebuild take?

Nobody is going to be able to tell you how old it is from looking at it, either.

it takes considerably longer than that for me.

motor swap probably 4 hours, head rebuilt (not including time at the shop) probably 2 hours.

people have taken out old belts at various mileages, some might have an idea by comparing this to what they have personally seen in their old belts.

Looks REALLY old!

thank you, finally some feedback on the op question.

[llll1l1ll]

Looks like it has some rust on it.

How long ago was the engine ran?

[2.5-12]

just bought the car, PO didn't know the history.

hard to say.

[nando]

it takes considerably longer than that for me.

motor swap probably 4 hours, head rebuilt (not including time at the shop) probably 2 hours.



thank you, finally some feedback on the op question.

okay, now add another 12 hours to that head rebuild (2 hours? seriously?) to remove and replace it. And a full swap in 4 hours? but you can't change a timing belt in less than 2 hours?

also, I'm pretty sure E30Gus was being sarcastic.

stupid question = stupid answer

[Farbin Kaiber]

x Everything nando said.

[2.5-12]

takes me less time to get the head off an M20 than it does to get the timing belt changed, I know thats not really a valid comparison because of the costs and outside time associated with new gaskets/studs and valve job at a minimum.

I have no issue with replacing timing belts, I have done it plenty of times on my various M20s over the years but I have never known the mileage on the belts I have changed and they have almost all shown signs of cracking, etc.

I also know that the canned response (that may very well be true) is to replace it if you dont have a documented belt on the engine but in this case, I am asking the question: those of you who have had your M20s long enough to have changed a documented belt with a new one, does this belt look better or worse than the ones you have swapped out.

I will, of course swap the belt eventually but I would like to know if I can wait till' the end of the summer when I have more time or if I should be taking time off to get this done now.

[nando]

I've changed like 6 belts on my engine.

want me to guess? it looks like it's 10 years old. How useless is that?

you can't tell the age of it by looking at it. end of story.

[2.5-12]

I've changed like 6 belts on my engine.

want me to guess? it looks like it's 10 years old. How useless is that?

you can't tell the age of it by looking at it. end of story.

I am not really asking age, I am asking number of miles. as far as I am concerned, age is irrelevant on these unless its obvious the car hasn't been touched in 10 years.

[nando]

okay. it has 71,423 miles?

still a useless guess. sorry my answer isn't what you wanted to hear..

and yes age IS relevant. A 20 year old belt with 5 miles on it is just as dangerous as a 3 year old belt with 60,000 miles on it.