When should I rebuild the head/engine?

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twenty
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Post Fri Aug 27, 2021 12:16 pm

Hi There,

I'm about to ask a somewhat open ended question so please don't mind me and blame it on my lack of car/engine knowledge.

As you'll see from my signature, I have a a 1990 pre-facelift 325i convertible. It's an auto on 159k miles and I've only owned it since last year. The car runs and works fine regardless of age and I've just came back from a 300 mile trip that went smooth with no issues, including no overheating - the coolant temp stayed left of middle as expected. I averaged 27mpg without driving fast and furious which is somewhat lower than expected but I guess I can't complain it being an auto.

Anyway, I'm mindful that it's an old car with high mileage and probably in need of some engine TLC, so with that in mind I've been contemplating rebuilding the engine within reason. Given this, my next questions are:

- What should I look at getting changed/done?
- How much should I spend doing this?
- Who should do it (I'm in London and previously used BMR for all the major works)
- What other additional things I should carry out while this work is carried out?

Thanks!
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martauto
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Post Fri Aug 27, 2021 1:44 pm

I would ask at BMR and they should offer sound advise.
If I were you, "if it`s not broke then dont fix it" winkeye winkeye

Mart.
Only the E46 cab left now.
Just got too old.
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flybynite
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Post Fri Aug 27, 2021 3:48 pm

The 325i was never renowned for economy, quite the opposite. Mine was a lot thirstier than my 323i C1 which is one of the reasons why I moved on from it to an E36 M3 which ironically was nearly twice the power and did better mpg. 27 is not far off the mark.

If the oil has been changed regularly and it hasn't been ragged when cold or overheated, then 200k shouldn't be a problem. If something was going to give it probably would have by now.

Mart is right, if it ain't broke........

To put your mind at rest you could get it checked over, compressions checked and valves adjusted properly, maybe new cambelt etc, no better place than BMR, you would get an honest opinion as you know.
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martauto
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Post Fri Aug 27, 2021 4:40 pm

flybynite wrote:
Fri Aug 27, 2021 3:48 pm
The 325i was never renowned for economy, quite the opposite. Mine was a lot thirstier than my 323i C1 which is one of the reasons why I moved on from it to an E36 M3 which ironically was nearly twice the power and did better mpg. 27 is not far off the mark.

If the oil has been changed regularly and it hasn't been ragged when cold or overheated, then 200k shouldn't be a problem. If something was going to give it probably would have by now.

Mart is right, if it ain't broke........

To put your mind at rest you could get it checked over, compressions checked and valves adjusted properly, maybe new cambelt etc, no better place than BMR, you would get an honest opinion as you know.
There you go......... :clap: :clap:

Mart.
Only the E46 cab left now.
Just got too old.
twenty
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Post Fri Aug 27, 2021 4:59 pm

flybynite wrote:
Fri Aug 27, 2021 3:48 pm
The 325i was never renowned for economy, quite the opposite. Mine was a lot thirstier than my 323i C1 which is one of the reasons why I moved on from it to an E36 M3 which ironically was nearly twice the power and did better mpg. 27 is not far off the mark.

If the oil has been changed regularly and it hasn't been ragged when cold or overheated, then 200k shouldn't be a problem. If something was going to give it probably would have by now.

Mart is right, if it ain't broke........

To put your mind at rest you could get it checked over, compressions checked and valves adjusted properly, maybe new cambelt etc, no better place than BMR, you would get an honest opinion as you know.
Thanks for this. I’ll wait till the next service is due for compression test as recommended.
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Contours
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Post Tue Aug 31, 2021 3:44 pm

I would say that 160k is low mileage--I have 350k on mine and its as good as the day I got it many years ago. As stated, regular oil changes are key.
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martauto
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Post Tue Aug 31, 2021 4:03 pm

Contours wrote:
Tue Aug 31, 2021 3:44 pm
I would say that 160k is low mileage--I have 350k on mine and its as good as the day I got it many years ago. As stated, regular oil changes are key.
This is testament to what I have said for years and years and years, oil is cheap, engines are not winkeye
I change oil and filter on both my cars twice a year no matter what the book says.
Buy in bulk, deffinately oil as it is soooooooo much cheaper to buy 25 litres and filters are very cheap when bought in bulk too.

Mart.
Only the E46 cab left now.
Just got too old.
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Contours
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Post Tue Aug 31, 2021 7:00 pm

True, Mart. Bmw should have included in their service manual that if you are keeping this car for 30 years then halve the service intervals.