Hi all (especially Tech )

It seems like it's time for a new head gasket and it's looking more and more like I will have to do it myself (dealers and indies want to charge a fortune for labour).

Now, I realise that I will have to take off the valve cover, inlet and exhaust manifold and timing belt. Anything I should look out for? Is it a good idea to have the head skimmed? Do they have to take it apart to skim it? Anything else I should do/look for while the motor is open? When putting it all back together, other than cleaning the surfaces where the gasket goes, is there anything else I need to check, do I need to use some of that silicone gasket stuff? When retorquing the new head bolts, do you have to do it in a certain pattern?

Any and all tips are welcome as I have never done this before, but I'm not scared

Cheers.

 

Unless you can get ahold of the specs for assembly, don't do it blind. Every internal combustion engine I've ever seen a manual for has torque specs and specific bolting pattern. Why? Because you're trying to keep the mating surfaces as flat as possible. I'm talking motors from Briggs & Stratton, Harley Davidson, Ford, GM, etc. I suspect piston airplane engines are even stricter about this since you don't want to create a gap which will lead to a blown head gasket. And trust me on this one, you'll do better guessing the next Lotto numbers than you will guessing torquiing sequences and torque values. They make little sense to the layperson.

Head gaskets usually aren't repair/replace items. Why do you think your's needs to be replaced?

 

Car is loosing coolant (did a pressure test already and have sorted all the "external" leaks) and sometimes after I have "floored" it and start it again afterwards, it runs a little rough.

It has seriously overheated about 2 or 3 times in the last couple of months (due to major coolant leaks) and I'm sure that caused it or at very least didn't help things.

Although I have never done a head gasket, I know there is funny things like torque patterns etc, that is why I put tech's name in the post, that man knows his way around a Volvo

Cheers.

 

You may have a small leak in the head gasket. Is the oil "creamy" looking in the crankcase? Is there evaporated coolant anywhere along the head/block seam? Coolant loss could mean something as serious as a cracked block, or as simple as a leaky freeze plug. Or even a leaky heater core. Does the car stream "steam" from the exhaust when you floor it? There's a test (low pressure) for leaky cooling systems whose name I've forgotten over the years.

My point is that you can't be sure its the head gasket that's causing coolant loss. Overheating, where there is a loss of coolant, doesn't prove the head gasket is shot. If it were mine, I'd be tempted to have professional diagnosis done before I undertook replacement of the head gasket especially without a thorough service manual. And if the overheat was substantial, you might be dealing with warped surfaces on the head which you'll need to check for or you'll never seal any leak there.

I'll defer to those who have actually done the work on Volvo, however.

 

The head can be machined without taking all the valves out.
Has anyone done the block test to see if it is bad?
Is there coolant in the spark plug holes?

You should try to make a cam lock tool as well to help with putting it back together.

 

The oil is not creamy and I don't notice any steam when driving. The coolant loss is quite slow so might not be noticeable in these ways (only have to put in about 500ml a week).

What is a freeze plug?

Have not checked for coolant in spark plug holes, what would this indicate?

What is a block test? Speaking of the block, would this also need to be machined or is it mainly just the head that warps?

With the head off, is it possibly to do the piston rings if they look a little warn?

After battling to get the timing right when I changed my cam belt, I'm definitely getting something to lock the cams with

 

I just got done with a head job yesturday on a 5cyl turbo. You have to be careful when pulling the cam cover off, you have to use a butterly type tool that remvoes pressure off the cams equally. If not, you run the risk of breaking the cams or the cover itself. Also the head bolts do have to be repalced and torqued to a specific spec, which is a step torque + angle torque. You will have to check the deck clearence yourself on the block. The car i did it on overheated badly and the deck was ok. These normally are ok, just the head warps easily. If you dont have that much expierence with work like this, i would recomend to have someone do it.

 

Have you checked to make sure the heater core is not leaking?

The block test checks for exhaust gasses on the coolant system.

 

Heater core seems fine. I permanently have a white paper towel underneath it so I can see if it is leaking.

Do you mean a sniffer test? I think that is what we call it. Not yet, going to try and find a diy kit and also a compression tester.

 

Freeze plug is a plug in the block which is usually low-mounted to prevent block cracking from expanding frozen coolant. I know they're called something else in Australia, but I forget what they're called. They are meant to pop out as the coolant freezes. I'm seen them loose on cars like GM small blocks.

 

Read this it explains and shows a picture of it.
http://images.google.com/imgres?imgu...n%26safe%3Doff

 

I had almost exactly the same symptoms on my 2002 V70 XC. I got the test which indicates whether there are engine fumes getting into the coolant (liquid changes colour) - there was.

Turns out it was the head gasket -blown between cylinders 3 and 4. However, the engine never overheated, and its never been pushed very hard. I am now wondering if there could be an underlying problem which caused the gasket to blow.

Anyway - good luck