Cleaning head

[dtom4]

ok-so I have the head off my 93 16V for the gasket replacement. Its a chocolate mess and I sprayed the head down with brake cleaner. 3 of the piston tops are black with carbon as are the valves. Whats the best way to clean up all the crud before reinstalling everything? I've read about wire brushing but that sorta scares me. It doean't look too bad but I'd like to clean it up as much as possible. TIA

[Matthew]

Have a look here for tips on cleaning the head:
http://www.saabcentral.com/forums/sh...ad.php?t=64480

I have a 16v head gasket to do soon, and I'll be stripping the heasd to have it hot-tanked. That should properly clean everything off the head. You can leave the valve gear (minus cams) in place for the cleaning, although I may strip mine completely.

As for the piston tops, I use brake cleaner and a metal pot scrubber. Push some grease into the gap between the pistons and the cylinder bore, to catch junk and rubbish. Then clean out the grease with a rag.

[dtom4]

Originally Posted by Matthew

Have a look here for tips on cleaning the head:
http://www.saabcentral.com/forums/sh...ad.php?t=64480

I have a 16v head gasket to do soon, and I'll be stripping the heasd to have it hot-tanked. That should properly clean everything off the head. You can leave the valve gear (minus cams) in place for the cleaning, although I may strip mine completely.

As for the piston tops, I use brake cleaner and a metal pot scrubber. Push some grease into the gap between the pistons and the cylinder bore, to catch junk and rubbish. Then clean out the grease with a rag.

Thanks Mathew. Great writeup. One question I forgot to ask, the new headgasket is somewhat different than the original. Some cooling passage s differ in shape. The new gasket has a few smaller circular passage openings where the original is the off oval shape of the engine passage. I thought I read somewhere the new gaskets are different and block some passages but would like to make sure. Seems like this would restrict coolant flow. Thanks again.

[Matthew]

Yes, the newer gaskets are different. The head gasket design did change over the years.

If you bought a genuine Saab (Elring) gasket for your car's year, then you have nothing to worry about

[dtom4]

Originally Posted by Matthew

Yes, the newer gaskets are different. The head gasket design did change over the years.

If you bought a genuine Saab (Elring) gasket for your car's year, then you have nothing to worry about

Great! Yes its genuine Elring Thanks again.

[idiot_saabvant]

I've used products like Lucas Fuel Suppliment and Injector Cleaner (or equivalent) to remove stuck glowplugs (caused by carbon build up) from my diesel engine. Let em soak overnight. I've also used it to clean piston domes on 2-cycle engines. But as Matthew stated, the best is hot tank.

[dtom4]

Originally Posted by idiot_saabvant

I've used products like Lucas Fuel Suppliment and Injector Cleaner (or equivalent) to remove stuck glowplugs (caused by carbon build up) from my diesel engine. Let em soak overnight. I've also used it to clean piston domes on 2-cycle engines. But as Matthew stated, the best is hot tank.

Thanks for the tips. I had some time today to tackle it a bit and ended up doing as Mathew suggestted and cleaned it up with brake cleaner, fine sandpaper and brake cleaner.
I got the head back on but now I'm running into an issue with the chain tensioner. When I bolt it down it puts so much tension on the chain it binds the engine down so it can't be rotated by hand. I was trying to turn the engine to check tdc and realized the it was so tight the engine was locked up. I there an adjustment? There's a spring in the tensioner and the actual adjustment rod seems to be spring loaded but rachetted so it can only extend and not retract. Thanks again for everyones assistance.

[Matt88S]

Oh dear, you did reset the tensioner before you bolted it back on didn't you?

[SteveTheFolkie]

there's a write up on adjusting the tension - can't recall who did it BUT they showed using a small screwdriver to disengage the rachette so the rod would retract - easing the tension - one of you young pups probably has a better memory than mine - one thing that sticks in my mind was that they shoved either a large screwdriver or other tool down to keep the tensioner from extending all the way out - the tip on the rachette (which I've now misspelled twice I believe) was further down the thread -

[Matthew]

Originally Posted by SteveTheFolkie

there's a write up on adjusting the tension - can't recall who did it

This one?
http://www.saabcentral.com/techhelp/...ming_chain.php

[dtom4]

Originally Posted by Matt88S

Oh dear, you did reset the tensioner before you bolted it back on didn't you?

Umm, whoops.....After posting I went back to the car and took the tensioner off again. Bentley and twinsaabs didn't mention anything about resetting the tensioner, only said to reinstall. Nothing broke and everything looked ok so I reset it and now everything seems ok. Hope there is no hidden damage.

The head is back on and I have it torqued to stage 2 at 59lbs. I tried going to the last step of an additional 1/4 turn but it is so tight I'm not sure it will make it. I got as far as about an 1/8 turn with my 2' breaker bar before giving up for the day and retorqued it back to 59. Gonna give it another shot this weekend.

[900t]

Did you use a new chain? If you used the old, probably not much of a big deal at all.

[dtom4]

Originally Posted by 900t

Did you use a new chain? If you used the old, probably not much of a big deal at all.

Yep, reused the old chain. Everything seems ok so I'll keep my fingers crossed. Thanks.

[900t]

Oh don't worry then - the tensioner was out enough for the old chain and you just put it back in at the same extension I'm guessing, if it ain't broke don't worry about it

[Matthew]

Originally Posted by dtom4

I tried going to the last step of an additional 1/4 turn but it is so tight I'm not sure it will make it. I got as far as about an 1/8 turn with my 2' breaker bar before giving up for the day and retorqued it back to 59. Gonna give it another shot this weekend.

The bolts will make it - the final 1/4 turn stage is very tight indeed. Dooable with a 2ft breaker bar though.

[900t]

I used a 1/2 inch drive ratchet with about a 1ft bar, with about a five foot length of heavy steel pipe (damn pipe weighed a good 25 kg!) and I only needed to push with my little finger