I was reading an article today and it said if the head gasket goes on a 2.8 it cant be repaired as the cylinder head bolts when torqued up stretch the threads in the block and dont tighten correctly ? Has any one heard of this ?
2.8 Head Gasket
- Thread starter D R Oldfield
- Start date
My 2.8 head gasket blew during the 2017 Forum euro trip. Something holed my radiator, lost my coolant and blew the head gasket. This happened on the first day of the trip.
When I got the car home I started the job to repair my car. I had the head skimmed and just as you read I found I couldn't tighten the head bolts to the correct torque as the threads in the aluminium block had pulled.
I actually redrilled all the holes and helicoiled them. This did the job and I got the car running again. Got it through it's next MOT but it suffered from high oil consumption there after.
I bought and fitted a replacement engine and it's been all good since.
When I got the car home I started the job to repair my car. I had the head skimmed and just as you read I found I couldn't tighten the head bolts to the correct torque as the threads in the aluminium block had pulled.
I actually redrilled all the holes and helicoiled them. This did the job and I got the car running again. Got it through it's next MOT but it suffered from high oil consumption there after.
I bought and fitted a replacement engine and it's been all good since.
The block threads will invariably strip on the last angle tighten - they were 'use once only' tbh.
Helicoils are alright but you need the long ones to give it the best chance. The steel TimeSerts are much better but I'm not sure if you can get any that are around 50 mm long.
Helicoils are alright but you need the long ones to give it the best chance. The steel TimeSerts are much better but I'm not sure if you can get any that are around 50 mm long.
so basically any head faults and its basically a new engine so the engines are disposable ?
That wasn't the intention but it's how it has panned out.
Single Vanos 2.8's are very rare now and ££££. US market cars (and E36, E39) had iron blocks similar to the previous M50. With the head off, timeserting the block isn't too tragic, just time consuming as you have to do all of them.
Single Vanos 2.8's are very rare now and ££££. US market cars (and E36, E39) had iron blocks similar to the previous M50. With the head off, timeserting the block isn't too tragic, just time consuming as you have to do all of them.
My M44 has a cast iron block so no such worries 
Sorry!!!
Sorry!!!
Should have kept my 1.9 , any hopefully get my 2.8 out of the garage in the next couple of weeks as I put it away 12 months ago as it was over heating when I left it running on my drive for about 45 mins hopefully its just a water pump or thermostat other wise i will be looking for a new engine !
A lot will depend on how much the cylinder head bows. On my car the head bowed on cylinders 3, 4 and 5. When I did the repair I used the long helicoils as Andy says. I was a bit apprehensive when it came to torquing the head down but it went OK.
While I had the head off I should have paid more attention to the condition of the bores. After the new engine was fitted I stripped the old engine and found that number 5 cylinder was badly scored, but the scoring was only on the bottom half of the cylinder bore.
While I had the head off I should have paid more attention to the condition of the bores. After the new engine was fitted I stripped the old engine and found that number 5 cylinder was badly scored, but the scoring was only on the bottom half of the cylinder bore.
Thanks for the information , i have rebuilt many petrol and diesel engines in the past usually old A series B series Xflows etc but nothing on the complexity of a M52 and would like to preserve the originality of this car and hopefully it will only be a water pump and or thermostat, i suppose only time will tell , i am even thinking about if i need to do the head just getting the engine completely reconditioned , does any one have any recommendations who could do it and what ever machining is required ?