740 GLE Head Gasket Replacement
 

Good day all, I’m new to the forum and Volvo ownership. I recently purchased a 740 GLE and have come to the conclusion that I need to replace the head gasket based on some things I read on this forum when I was trying to diagnose a misfire that I have.

I haven’t been able to find an old Chiltons manual or anything as of yet to help me with instructions and I was hoping somebody on here might have a guide to it or a video or anything that might help me to not screw this up.

any assistance, thoughts, or words of wisdom would be massively appreciated. Cheers.
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check out volvotips.com

thank you for the website. I tried to use it, but the pages say “under construction” and the menu doesn’t work. I’m going to try again later from a non-Mac and see if it will work.

I had same issue
 

You said you think the head gasket is bad based on diagnostics from this form. What exactly did you find to verify it. Low or no compression , water in the oil or oil in the water. Exhaust gasses in the coolant system. White smoke pouring out of the exhaust pipe or overheating. Be a little more specific before you dive into pulling the motor apart.

thats a 16 valve, so you have the DOHC B234F engine, instead of the more common B230F single cam. guessing the head gasket on a dohc is a more complex job.

but what jagtoes says..

Mom basing the diagnosis off the Volvo mechanics recommendation who took care of the car the last 15 years. It’s got no compression in the cylinder closest to the firewall and he told me the head has some stuck valves most likely the issue. I decided to try and remove the head to see what the issue was either the head gasket or the head itself etc. however I’ve been messing about with it and so far unsuccessful in removing it. Been tough as I’m not the most amazing mechanic and I can’t find any guide or info on how to take this car apart this far. Currently stuck trying to get the lower two belts off the engine to get at the lower timing cover.

OK no compression can mean a few things but pulling the head might be the next step. Apparently it sound like you are going to have a steep learning curve based on your progress. Worse case just cut the belts off as you'll need to replace them anyway. Also with the twin cam motors you'll need to make sure the timing is set to the marks prior to removing the belts and the head. Everything is straight forward as you need to remove anything attached to the head then the head itself. Good luck

re stuck valves, with the valve cover off you should be able to check each valve with shims, any stuck valve would be pretty obvious.

I figured if I pulled the head off I could see multiple things potentially wrong and do the gaskets I would’ve needed to probably do anyway. The head removal is straight forward to me I’m just stuck at figuring out how to detension the two lower belts as there isn’t a tensioner pulley.

My concern with cutting them was that I don’t know how to tension them upon the rebuild. Trying to figure it out so I know how it goes together. I see all the tensioners for my cam belts and the alternator belt just not the power steering and AC

the power steering pump and a/c compressor should be mounted on pivots, each with a tensioning screw. similar to the alternator.

here's the PS pump, see part #22, thats the tension adjuster, it moves the whole pump (#3) via brackets #20 and #21. the AC compressor has a similar setup.

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