740 head removal question
 

Hey all I’m trying to obtain some info on how to properly remove the head from my GLE. It’s the DOHC and all the data I can come up with online is for the SOHC. My concern is that the head bolts appear to be under the cams and I didn’t want to remove them as I have no idea what will happen when/if I remove them or how important it is to get them back exactly as they were. If anyone has tackled this job I’d greatly appreciate a run down and/or some helpful tips.

Never done a 16V myself but logically if the bolts are under the cams, the cams have to come off. You'll have to retime everything afterwards anyway. I'd set the timing marks where they have to be and take off the cams.

Thanks for the reply. My worry was with taking the cans off ensuring I put them back in the same position which I figured I could mark. I just wasn’t sure what would come apart when I took off the cams. It’s my first time removing a head so I’m overly concerned that I butcher something.

You should have the timing and torque specs, turn the engine to where the marks are where they are supposed to be, and take it all apart. The 16V is trickier but not too bad from what I've heard... It's impossible to take off the head without disturbing the timing even on a 8V--I've tried it, it doesn't work. Obviously the 16V being "interference" engine, gotta be careful or valves will crunch.

The timing I do have set correctly, but I’ve yet to find the torque specs for the head I have to do some more digging for that. Now I’m worried about disturbing the timing when I take it apart and not getting it exactly the same on the reinstallation. I wish there was a video of someone doing a head job on one of these cars, but no dice. There’s a small chance the engine is damaged anyway so it may never get past the removal process anyway though.

What is the reason for wanting to remove the head. Did you do a compression check or is the head leaking. Normal procedure is to bring cyl. #1 up to TDC and verify all timing marks on the cams and harmonic balance are aligned. Then take everything apart. If you have 0 compression in 1 or more cylinders then you most likely bent some valves. Do we assume the timing belt didn't break.

I purchased the car with a misfire in cylinder 4 which also has no compression. It’s weak on 3 and fine on 1 and 2. The assumption is that there is a stuck or bent valve/valves and the head gasket may be bad. However the car didn’t overheat, no coolant in the oil, and the timing belt didn’t snap or come off and was just done about 25k ago(still looks new). I set the timing as per a diagram I was given from another helpful member on this forum. So i was planning to pull the head and see what’s happening under there if it’s just head work I need or the lower portion of the engine is damaged. I’m trying to stick to a budget on the project and figured I could disassemble and reassemble it after I get the head and the engine looked at by someone with actual knowledge vs a shadetree repairman like myself, but’s it’s a first time for me doing this particular thing without any instructions or references like a Haynes manual or something.

You are on the right track, most likely you have a bad HG, a burnt valve a distinct second possibility, bent or stuck valve not likely. So just continue disassembly and once the head is off you will know more.

Thanks for the information and the words of encouragement. I don’t know if this is actually true or not, but after buying my car I talked to some specialist mechanics that said these 16 Valve cars aren’t very common anymore because of complicated engine issues so I’m hoping to save this one

Very true! I have had many, many Volvos, never a 16V. Back in the day I avoided them on purpose, now would love to get one but all these Red Blocks are getting rare in a decent condition. Same as the 960, much more complicated than B230...

The 16V is really not that bad except for the interference engine but if you keep on top of the belt and tensioner and associated there is nothing different beyond that. Once you get it going you should be all right, even if you need a valve--machine shops do wonders and are not expensive considering...

Yeah I was hoping everything else would have held up
decently and I won’t run into too many other crazy issues. I’ve been looking through to make sure I replace every little thing related to the timing and balancing I can while the head is off so I don’t have to worry about it for a few years. As for the head a local shop quoted me $170 for a pressure test and shaving of the surface. I’m hoping it’s not much more than double that if I need head work

You don't need to shave the head unless it's warped. First take it off, go from there. You'll be able to tell what's wrong, may not even need a machine shop visit.
How many miles on this car? One great thing about Volvo is that they seem to usually need less than you fear!