Hi all, I have an old Maserati Biturbo that I bought in a non-running condition. It had a bad engine so I sourced a replacement used engine.
I got everything back together and have been seeing a lot of smoke from the tailpipe.
I initially did a compression test:
cylinder 1 - 120
cylinder 2 - 115
cylinder 3 - 130
cylinder 4 - 123
cylinder 5 - 118
cylinder 6 - 118
not super high but all within 10% of each other.
No real smoke until it heated up a little bit and then really heavy at high revs - then when warm pretty much all the time.
At that point I thought maybe the turbo was blown or perhaps there were valve stem seals blown. After reading more about it, I figured it was the turbo on one side or another.
I pulled the exhaust Y pipe and:
Passenger's side:
Driver's side:
So clearly an issue on just that side. I figured the turbo on just that side blew so I pulled the engine to get at it and upon pulling the exhaust manifold off the head it was clear that the oil was coming into the system ahead of the turbo:
So then I figured that a valve stem seal had blown on that cylinder. I pulled both heads and cleaned up the valves from a LOT of oily soot and replaced all seals.
It was the top left cylinder in the below picture - cleaner than the rest due to burning oil right?
I did find a bad seal on this intake valve - note the soot:
Here's the cylinder in question:
a few scratches but nothing with any depth to it at all.
All the valves fit in the guides properly and the cylinder sleeve diameters all check out per specs
So I buttoned it all back up
All fixed right? - no
I got it back together and still smoking like crazy. Here's the view right out of the exhaust manifold.
[video:youtube]https://www.youtube.com/edit?o=U&video_id=WYnkPgDsHFI[/video]
I pulled the turbo on that side again and same source of oil.
So, is this a simple case of stuck or broken rings? Could anything else have caused this problem? The good compression in cylinder #4 (the fouled cylinder) has me confused
I also had a bit of gas in my oil early on but I have chalked that up to excessive cranking with the distributor cap 180 degrees off (whoops!)
Thanks for your comments
I got everything back together and have been seeing a lot of smoke from the tailpipe.
I initially did a compression test:
cylinder 1 - 120
cylinder 2 - 115
cylinder 3 - 130
cylinder 4 - 123
cylinder 5 - 118
cylinder 6 - 118
not super high but all within 10% of each other.
No real smoke until it heated up a little bit and then really heavy at high revs - then when warm pretty much all the time.
At that point I thought maybe the turbo was blown or perhaps there were valve stem seals blown. After reading more about it, I figured it was the turbo on one side or another.
I pulled the exhaust Y pipe and:
Passenger's side:
Driver's side:
So clearly an issue on just that side. I figured the turbo on just that side blew so I pulled the engine to get at it and upon pulling the exhaust manifold off the head it was clear that the oil was coming into the system ahead of the turbo:
So then I figured that a valve stem seal had blown on that cylinder. I pulled both heads and cleaned up the valves from a LOT of oily soot and replaced all seals.
It was the top left cylinder in the below picture - cleaner than the rest due to burning oil right?
I did find a bad seal on this intake valve - note the soot:
Here's the cylinder in question:
a few scratches but nothing with any depth to it at all.
All the valves fit in the guides properly and the cylinder sleeve diameters all check out per specs
So I buttoned it all back up
All fixed right? - no
I got it back together and still smoking like crazy. Here's the view right out of the exhaust manifold.
[video:youtube]https://www.youtube.com/edit?o=U&video_id=WYnkPgDsHFI[/video]
I pulled the turbo on that side again and same source of oil.
So, is this a simple case of stuck or broken rings? Could anything else have caused this problem? The good compression in cylinder #4 (the fouled cylinder) has me confused
I also had a bit of gas in my oil early on but I have chalked that up to excessive cranking with the distributor cap 180 degrees off (whoops!)
Thanks for your comments
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