Head Gasket replacement

[DaveM]

Any one got a view on this:

My engine (25S3 M52 single vanos 1998) suffered an over heating problem due to a local garage failing to replace the coolant and radiator cap !! This was quickly remedied by a local Dealer who replaced the thermostat, engine sensor and secondary cooling fan. Also perfomed block and compression test, everthing reported normal and fit for purpose. Not so. The head gasket subsequently developed a small leak which blewout quite severely on the first long journey (3 hours constant use at 3000rpm). The temperature guage was midway in the red for about 5 miles before the blowout. Ok I should have stopped but didn't realise how serious it was.

I need some advice from seasoned mechanics. Is a total power loss usual in these circumstances or has the engine suffered from seizure and caused secondary damage (i.e big end, cam shaft, piston rings, warped head). It completely cut out, lost all power and seems to have lost compression across all 6 cylinders ! Is the power loss due to a seizure or does the EMU recognise a problem affecting the combustion cycle and shut down as a fail safe ?

I need to understand the potential engine damage before investing in a repair discovery expense - the estimates frighten me and I may be faced with £1000's more when they open it up. The engine has been very well maintained and was in otherwise perfect running order. My other option is a salvage engine replacement which would be cheaper all round.

Assuming it is a straight forward blow out with no secondary damage, any views on having the head skimmed to avoid recurrence of the problem ?

[Dan]

replace the whole motor. that's a lot of work to do IMHO.

[DaveM]

thanks Dan IMHO (not my lingo ?)Are you agreeing that a replacement is an easier option ?

[Dan]

In My Honest/Humble Opinion

yeah, when your motor is busted up like you said it is, unless you want to make it into a race motor, a complete replacement would make the most sense especially with the rings, warped head, etc...

[DaveM]

Ok got it ! Thanks for your advice, I just need to be sure the replacement is low mileage with history and that can be difficult to find ! Cheers.

[323I Junkie]

salage motor, replace it with an S52

[DaveM]

Cheers junkie , excuse my ignorance - what is an S52 ? Will it be compatible with the M52 running gear without mods ?

[E34N]

S52 is an M3 engine... usually can be found on various forums and classified ads (ie. Craigslist)

[323I Junkie]

Cheers junkie , excuse my ignorance - what is an S52 ? Will it be compatible with the M52 running gear without mods ?


s50/s52 is the hottest swap i know of for replacing a 2.3/2.5/2.8 i6..theres oodles of writeups on this very forum as well as internet sites. When search works again.,..

It would be a hell of a time to do it too

[Divy]

Any one got a view on this:

My engine (25S3 M52 single vanos 1998) suffered an over heating problem due to a local garage failing to replace the coolant and radiator cap !! This was quickly remedied by a local Dealer who replaced the thermostat, engine sensor and secondary cooling fan. Also perfomed block and compression test, everthing reported normal and fit for purpose. Not so. The head gasket subsequently developed a small leak which blewout quite severely on the first long journey (3 hours constant use at 3000rpm). The temperature guage was midway in the red for about 5 miles before the blowout. Ok I should have stopped but didn't realise how serious it was.

I need some advice from seasoned mechanics. Is a total power loss usual in these circumstances or has the engine suffered from seizure and caused secondary damage (i.e big end, cam shaft, piston rings, warped head). It completely cut out, lost all power and seems to have lost compression across all 6 cylinders ! Is the power loss due to a seizure or does the EMU recognise a problem affecting the combustion cycle and shut down as a fail safe ?

I need to understand the potential engine damage before investing in a repair discovery expense - the estimates frighten me and I may be faced with £1000's more when they open it up. The engine has been very well maintained and was in otherwise perfect running order. My other option is a salvage engine replacement which would be cheaper all round.

Assuming it is a straight forward blow out with no secondary damage, any views on having the head skimmed to avoid recurrence of the problem ?

I'd say you get an estimate on a replacement motor and send the bill to the local garage that started this whole mess.

[Lscman]

...........The temperature guage was midway in the red for about 5 miles before the blowout. Ok I should have stopped but didn't realise how serious it was.

I need some advice from seasoned mechanics. Is a total power loss usual in these circumstances or has the engine suffered from seizure and caused secondary damage (i.e big end, cam shaft, piston rings, warped head). It completely cut out, lost all power and seems to have lost compression across all 6 cylinders !

Five miles with little or no water.......guy, you ran the car to failure in the first 2 or 3 miles. With low water, the coolant temps will not accurately read out on the temp gauge and the water will no longer circulate. The most critical portions of the motor go dry (deck and head). A falsely low temp reading can result once flow and level drops because the liquid temp sensor can't and won't measure coolant system air/gas temp.

The extra couple miles you got out of it cost you a motor. The result is warpage &/or crack damage from running a water cooled motor in the no cooling mode. It will likely cost more to rebuild than it's worth & teardown for measurement and inspection adds a lot to the service bill.

Next time, stop immediately and get a tow within 100' or so. This makes it an $800 gasket job instead of a motor replacement. The cost per mile is too high to justify "a run it run until it drops" strategy. It makes no sense, unless you're driving through Bagdad with no escort. In this age of cell phones, there's seldom an excuse for driving with warning messages on the dash or steam from the hood. You pay. Same thing goes for running a flat tire until it shreds and the rim is destroyed. How many of us have seen that? A car that needs a $12 patch or plug repair suddenly needs a new $200 tire and $300 wheel 5 mi later.

My wife wouldn't dare do that to her minivan, after I sat her down & explained things to her the week after we got married. Thank goodness, since she lost the serpentine belt a week leter and had no water pump function. It cost me $29 and about 30 minutes to repair on the street because she stopped within a block....no tow needed. If she ran it for 5 miles, it could have cost me $5K.