Mahle or volvo piston rings? 850 - B5202S

Kokonradus · Post by **Kokonradus** » 05 Oct 2023, 11:03

Hello,

I am doing general overhaul on my volvo 850 B5202S engine. I ordered the only pistons on market (MAHLE) for this models in 2. oversize and of course I ordered 2os rings (original Volvo). But I found out that pistons are already with rings on.

Should I get off mahle rings from all pistons and put on volvo rings? Or is it just a waste of time and quality is equal? Cause I read somewhere that Mahle is one of OEM suppliers for volvo with these parts.

Thanks for your opinion

Post by **misha** » 05 Oct 2023, 15:44

Yes...Mahle is oem.

Post by **ZionXIX** » 10 Oct 2023, 13:49

Are you having the cylinders bored out? Or just replacing the pistons?

Post by **foggydogg** » 11 Oct 2023, 10:03

Kokonradus wrote: 05 Oct 2023, 11:03 Hello,

I am doing general overhaul on my volvo 850 B5202S engine. I ordered the only pistons on market (MAHLE) for this models in 2. oversize and of course I ordered 2os rings (original Volvo). But I found out that pistons are already with rings on.

Should I get off mahle rings from all pistons and put on volvo rings? Or is it just a waste of time and quality is equal? Cause I read somewhere that Mahle is one of OEM suppliers for volvo with these parts.

Thanks for your opinion

Volvo doesn't make pistons - or piston rings. The rings that came on the pistons are fine, but obviously a careful craftsperson assembling an engine in a tradesman-like fashion will fit the rings to the individual rebored cylinders.

Kokonradus · Post by **Kokonradus** » 11 Oct 2023, 11:19

Cylinder walls were worn out to dimensions almost same as 2. oversize (-0,4 mm) but my engine shop did the best and successfully rebored it to the size at least on most of track where pistons run. Hope it will run good. Rest of engine was good. Crankshaft main and connecting rod sizes were all in like-new condition and sizes (within manufacturers tolerances, close to new). Valves were like new as well.