Hello everyone. I just joined this site and I'm hoping someone with more knowledge than I would help me. I just purchased a 1999 Volvo C70 Turbo Convertible. The engine is a 2.4L B5254T and the head has the casting #1001773. The block looks to be okay but the head is shot, overheating has that effect. What heads are interchangeable with this? I'm looking at a very nice head with the casting number 1001716 that came off of a 1998 B5254T engine and also a 2000 head that came off of a B5254T engine. I'm well versed in Chevy's but this is the first Volvo I have ever owned and I'm a bit leary of interchanging this DOHC. Any help would be greatly appreciated.

 

Hello, I read your post and couldn't help but reply. I have the same problem with my C70 turbo which is also a 99. My head is cracked due to overheating and I'm not sure if I need to replace the engine or just change the head. I had one mechanic tell me if the head goes then the engine is probably shot. This might be a strange question but how do you know if the engine is unaffected when the engine header overheats and cracks. Thanks in advance

 

Hufilm, I cannot be 100% sure BUT I am VERY confident that it is, and here's why. I don't know what happened to make your head overheat but if it was like mine it was due to a cracked radiator and the loss of coolant. With the law of gravity being constant, the FIRST thing that will lose coolant protection will be the head. Even when the water pump won't pump coolant any longer, there is still coolant in the block. PLUS, the oil pump is still pumping oil which is not only the needed lubrication but it is also a coolant. Over 90% of the heat generated in an engine leaves the engine in the form of exhaust, which travels through the exhaust ports in the head. Now, with the head being unprotected and the transference of heat through aluminum being extremely efficient, the head will heat to destruction extremely fast. This is why my head is warped 15 thousandths on the exhaust side but only 5 thousandths on the intake side. I also know that even though my head is now overheated, the block is somewhat protected from the heat transference efficiency of aluminum by the head gasket.
Here's how I checked the block. When I got the car, the very first thing I did was drain the remaining coolant by opening the pitcock on the bottom of the radiator. I then pulled all the spark plugs to check to see if any of the cylinders had coolant in them. Cylinder #3 had about a half an inch of coolant in it. I sucked out the coolant with a vaccuum and sprayed a little lubricant in each cylinder. With the plugs out, I rotated the engine briefly by turning the ignition. Sounded good. I then put the plugs back in and reinstalled the coil packs. I then started the engine and ran it for about 20 seconds. Sounds good. After removing the head I rotated the engine with a ratchet. Feels good. I then cleaned the mating surface, I checked for warp with a QUALITY straight edge by using a flashlight, to see light coming from under the straight edge as I laid it over the block in several positions. I also used a 2 thousandths feeler gauge that I laid on the block in several locations and then lay the straight edge over it to see if I could pull it out from under it without any friction. This block passed all my tests so, I will use it. I am also rebuilding the turbo because of the loss of coolant even though it seems to be okay. Although this is my first Volvo, this isn't the first aluminum engine I've redone. I highly recommend using Hylomar sealant on the head gasket. Hope this helps you out!

 

If the engine got hot enough to melt the plastic yyou should check the cylinder tapper to make sure they did not elongate the head you need to use is for 99 only with VVT
you cannot use a 98 and there are solid lifter and Hydo as well make sure to mark all lifters iin order and replace head bolts when doing this job ..use the oe sealant only omn the cam cover and lock the cams down ..do not use any sealant on the head gasket ..We have done
many of these engines and know from a fact when someone does not do it right we have more work in damage ..try to find a Volvo ONLY Tech in your area . ck coil packs for damage as well get a head set From Elring oe
all the best

 

Thank you very much for your reply dalaaz. I've got to admit, working on and researching this C70 engine has been very humbling, I've always prided myself on always doing all the work on my cars but I didn't expect the detail of this rebuild. I did find a '99 turbo head and I did mark all lifters. When the gasket set came, I noticed the difference in the head gasket coating so I was not going to use anything on the head gasket. I do have a new set of head bolts and will use the sealant for the cam cover that came with the gasket set, and to apply it with a fine roller, and have made the pull-down tools and cam lock as described in the manual to lock the cams down before installing the cover bolts. I do now realize that this engine rebuild is unlike the engines I've done before and I am paying attention to the manual and following it closely. As far as a Volvo tech in my area, not a possibility. I did check the coil packs when I rotated the engine and the plugs seemed to fire with good spark. Thank you very much for your reply, your advice is very much appreciated!! If there is anything else that you might want to tell this hillbilly, please do!