Cleaning old head gasket material

[yokotabrat]

I'm in the process of replacing the head gasket on my 92 and ran into something I wasn't quite expecting.

First question is what is everyone using to clean the old residue off the block and head if you are not having a machine shop refinish the surface? The factory service manual suggests a gasket scraper.

Now the problem I ran into was, just using the gasket scraper on the block caused some small surface scratches. They just barely catch with my fingernail. It seemed like WD40 combined with the gasket scraper worked better, but the damage had already been done.

Second question, should I be concerned if I'm going with another factory composite gasket? I would think it's not as big a deal as an MLS gasket that's dependent on the surface finish, but some of the scratches are near where the fire ring on the gasket would seal. Maybe wetsand with very fine sandpaper to buff out the scratches? If I scratched the cast iron block, I'm even more concerned about the cylinder head.

If you've made it this far, I'd appreciate some suggestions. Thanks!

[cyberslug]

I would recommend a 3m roloc pad. Not the brillo one but the one with the little plactic fingers. I heard the the brillo ones get abrasive stuff all over in the oil passages, rings and such. I used one and did a MLS no problem. Get the least abrasive one they sell.

http://multimedia.mmm.com/mws/mediawebserver.dyn?6666660Zjcf6lVs6EVs666EJmc7rrrr Q-

[rlarsen]

Yeah, Bert, a gasket scraper is nearly impossible to use on a head without damaging it. If you're using a composite gasket, I really wouldn't worry about it unless you gouged the hell out of it.

I would second Tony on the Roloc pad, I haven't used them, but it seems like less of a hassle than the "brillo" type pads I usually use (I have to stuff towels in the cylinders and passages). It might be a good idea to be careful either way, because that gasket material will go everywhere.

You can also sand the surfaces if you use a large sanding block (think, longer than the surface, at least in one dimension) if you're careful and use long, smooth strokes (I said long, smooth strokes). I use this technique when I'm "mirror" lapping for perfect MLS sealing.

[yokotabrat]

Thanks for the reply's, Tony and Ryan. I guess it was a good thing I started with the block and not the head. I didn't think a gasket scraper could scratch the block. Thanks again.

[cyberslug]

I wouldn't even mess with the head, just let the machine shop do it. You are having it true'd up right?

[yokotabrat]

I'm not planning on having the head decked if it's still straight. I'm going to check it with a straight edge to make sure. It's already been machined once, so I'm hoping it doesn't need it again, especially since I'm planning on using another OEM headgasket.

[dsm_gsx97]

I used Simple Green to break up the crap on the inside of my runners a year or two ago when I was just putting on a head gasket. It was amazing how well it worked breaking up all the build up in the exhaust runners. You could hear it all cracking like rice crispy's. I used a tooth brush with it to help speed things up.

This year when doing my head I used the $9.99 Super Degreaser from Arbor Freight for cleaning it. It says 20 parts water to 1 part of it. So I used it straight with a spray bottle (and rubber gloves of course). Worked well also with a tooth brush but not as well as that Simple Green did. However for cleaning just about anything else it worked amazing! Just bought a big $5 brush at Arbor freight and a bucket. Spray a few times on it and then brush it with the brush wetting it and rinsing it in bucket a water. My plasitic side panels to the engine look like they are brand new. A few sprays on anything that had oil build up and within minutes it would be spotless. Good for cleaning the engine bay with for sure.

[BlueVelocity]

I used Simple Green to break up the crap on the inside of my runners a year or two ago when I was just putting on a head gasket. It was amazing how well it worked breaking up all the build up in the exhaust runners. You could hear it all cracking like rice crispy's. I used a tooth brush with it to help speed things up.

This year when doing my head I used the $9.99 Super Degreaser from Arbor Freight for cleaning it. It says 20 parts water to 1 part of it. So I used it straight with a spray bottle (and rubber gloves of course). Worked well also with a tooth brush but not as well as that Simple Green did. However for cleaning just about anything else it worked amazing! Just bought a big $5 brush at Arbor freight and a bucket. Spray a few times on it and then brush it with the brush wetting it and rinsing it in bucket a water. My plasitic side panels to the engine look like they are brand new. A few sprays on anything that had oil build up and within minutes it would be spotless. Good for cleaning the engine bay with for sure.


Was it an electric toothbrush? :p

Erron S.

[cyberslug]

I'm not planning on having the head decked if it's still straight. I'm going to check it with a straight edge to make sure. It's already been machined once, so I'm hoping it doesn't need it again, especially since I'm planning on using another OEM headgasket.

So what brought you to this point? Usually, if the gasket goes the head is warped/distorted and need to be decked. It's not fun to do this twice ;)

[97TurboTalon]

It think it was a Teenage Mutant Ninja Turtle electric tooth brush. :D

[yokotabrat]

So what brought you to this point? Usually, if the gasket goes the head is warped/distorted and need to be decked. It's not fun to do this twice ;)

The gasket blew between cylinders 3 & 4. There was a little chunk missing there. It didn't blow because of overheating, so I'm hopeful (though not confident) it isn't warped. Gasket went because I miscalculated on my injector pulsewidth and tried to run 130% duty cycle. :)

I'll definitely check whether it's warped. I agree, it's not fun to do it twice. I just don't want to machine the head if it doesn't need it.

[fivetodrive]

I really like the small 3m pads but nothing seems to beat a wire wheel on a cordless drill. I take a few paper towels and plug the holes first though. I actually really like the blue wokshop towels the best though!

[renovatio]

First be certian that your head and block are true . Having a machine shop resurface is the best bet the money to have this done is well worth the time and effort you will spend doing it your self. But if you must, I like to use a new razor blade by itself to get the majority of the gasket off If you use it right you won't gall the head you just want to get under the gasket to get it off use the middle of the blade NOT THE EDGES. Then I use green scotch brite pads with carb cleaner to remove the rest of the gasket. watch to not let to the debris in to the oil passages. The abrasivness of the pad is determined by the color green is good on most aluminium parts (provided that you don't get to agressive). Typicly I don't use roloc discs because it's real easy create a low spot in the Aluminium that is around to the piece of gasket you are trying to remove. But if you must, the blue discs are the ones to use lightly on aluminium.