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Head gasket DIY on a 2005 XC90... Have any tips?

A mid-size luxury crossover SUV, the Volvo XC90 made its debut in 2002 at the Detroit Motor Show. Recognized for its safety, practicality, and comfort, the XC90 is a popular vehicle around the world. The XC90 proved to be very popular, and very good for Volvo's sales numbers, since its introduction in model year 2003 (North America).
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Head gasket DIY on a 2005 XC90... Have any tips?

Post by jeffstuckinpa »

hello everyone,

I have been in my 2005 xc90 for roughly a year... slowly getting jobs done all around the car... swapping in parts here and there.. Came across a little oil in 3 of the spark plugs it seems to me they were just swapped recently... I'm just trying to decide if I should tackle the daunting task of replacing my head gasket in the silver bullet, I have done job before on my maxima and prelude but never on a turbo car...

I found a listing here about doing a 850 head gasket but I haven't really found any step by step videos and or warnings out here in the interwebs specifically for the xc90..

any tips, pointers, warnings or advice for an avid wrench turner??

thanks in advance!
Last edited by matthew1 on Thu Aug 01, 2019 12:19 pm, edited 1 time in total.
Reason: improved title

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Post by RickHaleParker »

It could be spillage or leaking O rings between the top of the head and the Cam Cover.
Wipe the spark plug wells down, drive the car, check to see if it is leakage or not.
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Post by SuperHerman »

The job is pretty much the same as on the XC70, V70, V50, S60 and S80 with the same engine. You will actually have more space.

The turbo doesn't really cause any additional issues other than at the exhaust manifold - in reality the add is minor. Also some piping, but that is not a big deal either.

Generally all Volvo engines are pretty much the same - sure there are a few changes, but the basics you are seeing in the videos apply.

If you have VIDA check the Volvo specific procedure - if you do not get it. You don't even need to buy the code reader portion - just find the software and plug in your car details and then pull up the procedure.

Technically you can just replace the leaking spark plug o-rings and leave the head gasket undisturbed. The process is almost as bad as a head gasket - so depending on budget and miles on the engine it most likely would be worth freshening up the top end with a valve lap and new valve stem seals plus a general crud cleaning (also timing belt, water pump ...). Plus side is you will have the chance to change out all of your cam seals. Most of the seals and related parts come with the head gasket kit anyway so you may as well use them. At this point it may be worth dropping the oil pan for good measure and clean it out, the PCV drain can be cleaned and the dangerous o-rings replaced. After that you are golden for maintenance.

If you pull the cam cover - you can technically change the front cam seals by removing the cams and leaving the VVT hubs on by just sliding the seals off the long way. This will make the process a bit easier as VVT removal for some is a beast.

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Post by gstallons »

why do you think the head gasket has anything to do with oil on the spark plugs ?

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Post by SuperHerman »

First - you have two posts going on the same subject. In your other post you state you have coolant in the spark plug wells. That should not be there even with spills unless something incredible happened. Splashing coolant is unlikely.

Second - assuming you just have only oil in the spark plug wells gstallons is correct - you may not have a head gasket issue.

Due to the baffle under the oil cap, it slows oil filling and causes spilling which ends up in the spark plug wells. This is very common.

You need to eliminate this as the source of oil in the spark plug wells buy cleaning everything up and drive the car for a few hundred miles and then check again. If you have to add oil make sure none spills.

Of course if you have other signs of a blown head gasket you have to run through the possibility. Check the coolant for oil and check the oil for coolant. Look at the spark plugs to see if you have coolant leaking and shine a flashlight with the spark plug removed and compare all the piston tops to look for coolant cleaning. Look for signs of coolant and oil leaking around the cylinder head. Check for leaking coolant hoses which could have pushed fluid into the spark plug area. If you are still unsure check to see if the car is smoking, smell the exhaust and do a block gas test to see if coolant is in the combustion gas. You can also do a coolant system pressure test and compression test. That is the list I would go through to make sure the head gasket was not compromised.

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Post by Roger_850T »

I agree with SuperHerman - you need to figure out what's really going on first. It's pretty common for people to be sloppy filling oil, and/or a hard oil fill gasket, allowing oil to leak out, and it finds it's way into the spark plug holes. Is the oil more centered on the middle cylinders? I'd clean it out, install a new oil filler gasket, and see how it goes.

Have you done a compression test?

Coolant, if you have it, is a very different deal. Where is it coming from? Again, there's nowhere nearby for coolant to leak from - where's it coming from. Clean it out, and see if it comes back. Watch it closely!

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