head gasket, timing belt replacement - doable?

[gavint]

Hi all you car DIYers:

I bought a cheapie new old car in the fall - a 20 year old Opel (Vauxhall) Zafira.  In great shape for its age, generally, but a few months in the engine light popped on, and it's clear that there is leakage of coolant coming out of the head gasket.  I understand this could just be the head gasket, but could also be a warped or cracked engine block too at which point it may make sense just to drive it till it dies and throw it away.

I've got two general questions for those in the know:

Do head gasket repair products you feed into the cooling system actually work?

And is an engine tear-down to get at the head gasket doable for a handy, motivated amateur with a good repair manual?  In this car I would have to remove the alternator, timing belt, timing belt tensioner among other things.  So, I would replace the timing belt and water pump at the same time as the head gasket. 

What do you think?

[Paper Chaser]

Do head gasket repair products you feed into the cooling system actually work?

No

And is an engine tear-down to get at the head gasket doable for a handy, motivated amateur with a good repair manual? 

Yes

[middo]

As @Paper Chaser said, give the repairs a go.  But expect it to take time and knuckles.  If you do not have tools it becomes a lot harder.  Tools will increase the one-off cost of this repair.

[gavint]

Thanks for the replies!

Does it make sense to replace anything else at the same time - thermostat, sensors or the like? 

[Dave1442397]

Thanks for the replies!

Does it make sense to replace anything else at the same time - thermostat, sensors or the like?

From a quick YouTube search, that engine looks pretty easy to work on, so I wouldn't bother replacing anything that's easy to get to with everything in place. If parts are cheap and you would have to spend significant time removing other parts to gain access, then it's probably worth doing it. The thermostat and water pump are easy DIY jobs on my car - all I have to do is remove the air intake to get at them.

Be careful putting things back together. It looks like that head uses torque-to-yield bolts, which are one-time use bolts and must be replaced when putting things back together. Obviously you'll need a torque wrench to get that right, and maybe additional tools - see this video for an example: https://youtu.be/tjGq2RzU9FU

[BudgetSlasher]

Thanks for the replies!

Does it make sense to replace anything else at the same time - thermostat, sensors or the like?

The only reasons I can think to do anything else in connection with this project are 1) It is easier to do/get at with the disassembly already required and likely to need doing at some point during your ownership ("cheap insurance"), 2) There is a known weak-spot (and available corrective action) in this particular engine that could cause catastrophic failure if/when it happens, or 3) It is a maintenance item, especially the more important ones, that you have no idea or way of know if it has been done.

Otherwise just fix what is broken now and then do other items when then come up.

Regarding your coolant leak, have you checked to oil? If you pull the dipstick the oil looks like chocolate milk you've got coolant in the oil. Driving it like that can put some unnatural wear on the engine and needs to be addressed quickly.

Regarding you engine light, most cars have a light coolant ... but you have a check engine light on. I doubt it is related to the coolant, it could be minor or major. I think Europe has its own version of OBD, it is probably worthwhile for you to get a scanner and pull the exact code that is causing the light. In the US many auto parts store will read the codes for free (of course they hope to sell you the parts to fix it).

[HPstache]

A couple of thoughts for you.  First, are you sure it's coming from the head gasket?  Water pumps can sometimes have a weep hole that will let coolant drip out when they have failed to indicate it's time for a new pump.  They can often be in the same vicinity making it look like coolant is coming from the gasket.  It could also be coming from a head steam tube connection, a connection to the throttle body, and a number of other places that are not the head gasket but might be building up as a thin sheet on the head gasket edge from somewhere above.  In fact it's a little rare/less common for a gasket to leak out instead of into the combustion chamber, so second,  would also check the oil for evidence of water, or even under the oil fill cap is usually a light brown goo that you'll find if the HG is compromised.  Finally, I would say that a head gasket job is doable for a handy person, but you should go in eyes wide open that there are quite a few advanced concepts such as Torque to Yield head bolts, tightening patterns, checking for deck flatness, special sealants / thread locker applications, timing the crank to the cam(s) using timing marks, etc.  If you dive in and can't finish, most mechanics are not going to want to touch it.  Food for thought.

[zolotiyeruki]

How much car maintenance and repair have you done in the past?  How are you set for tools?

If you're new to car repair, a timing belt is a pretty big leap.  From a couple of videos I glanced through, it doesn't look as bad as what I've had to deal with (a Toyota Corolla and a Honda Odyssey), since the engineers did a good job of keeping that side of the engine clear of obstructions.

If the head gasket issue is simply a failed head gasket, then replacing it shouldn't be a huge deal, with Dave1442397's caveats about the torque-to-yield bolts.  If the head gasket leak is due to the engine overheating in the past, then it gets dicey--the head or block may have warped as a result of the overheat condition, and may need to be machined flat again before you reassemble the engine.

[BudgetSlasher]

Follow up thought, is this your only mode of transportation?

Before you jump in and give this a go, especially if you have next to know experience, ask yourself what you will do if it take you longer than anticipated to complete. How will you get to work, get more parts to finish the project, or run errands w/o the car?

[gavint]

Hi everyone, I appreciate the comments!

To answer the questions in there:
I do have some experience with working on cars, which is why I would consider taking on a bigger repair.  So far easier stuff for sure - Alternator replacement, oil changes, brakes and brake caliper replacement, trailer hitch installation including hard wiring it into the car's fuse box, and lots of smaller stuff.  I have an extensive tool library as I'm an independent landscaper (so good with tools and putting stuff together), somewhat lacking in specific car tools though.

This car is an absolute luxury for us, I bought it because it's kind of dumb from a tax, parking and comfort standpoint to use my work truck to take the family on vacations and also to allow for more spontaneous day trips.  We went without a car (besides my work truck) for six years.  If it sits for a week, it's not a big deal, we can get groceries by bike, streetcar or on foot.  For the price I paid, it just has to hold out for two more years and I'll be happy.

I did read the error code using the funny pedal pushing technique and counting how many times the check engine light blinks.  It is reading a bad fuel/air mixture, which lead me to think it was perhaps losing compression at the head gasket when I saw the leak.  The previous owner was required to install an emissions regulator in order to meet new standards, and suggested the new part doesn't communicate well with the computer causing the check engine light to sporadically come on and go off again.  Now though, the check engine light stays on all the time.  I think I might try to find that device and disconnect it to see if the engine light goes off - I don't know what it looks like or where it is though!

And I feel like a bit of a goof, but this is part of the fun with these sorts of projects - the learning curve.  I cleaned up the motor and chased the leak - rocker cover gasket is shot, oil leaking into the spark plug tubes and out onto the motor.  Much, much easier, bought the part yesterday and will install it today.  But, everyone's comments have been super helpful, and I will be taking on the timing belt and water pump - it is due before too long according to the maintenance plan. 

So thanks!
 

[Paper Chaser]

Assuming head gasket replacement is necessary based on a CEL for fuel/air mix seems like a huge leap to me.
If you can get the actual EOBD code that's triggering the CEL, that would be helpful with pin pointing potential causes.
Typical air/fuel issues can be cheap and easy to fix like filters, perhaps a new fuel injector, etc. They can also be more expensive things, but those are less common and we should check the cheap/easy stuff first.

[middo]

My car needs the MAF sensor to be cleaned every couple of years or it starts to throw codes.  I don't bother looking them up anymore, just get some cleaner and spray the sensor and wash it afterwards and all good.

As said earlier, I wouldn't be pulling the head unless the oil is frothy brown (or cappuccino) or it is significantly down in power.