Removing old headgasket from block?

[gpchris]

The gasket poped right off but it left weird residue. I got a lot of it off but theres still some on there. Anyone else have this problem? I can feel it. Its definitely raised from the surface but its on there good. Razor blade wont take it off either. I attached a scotch brite pad to my drill and that made no difference either. I dont want to hurt the surface.. and I really don't want to have it resurfaced. Would a light wirewheel at a modest speed be safe?

[GOT2B GM]

try a chemical gasket remover

[Z34guy]

[Schurkey]

Timely post. I'm dealing with a head gasket issue on my 3.4. Pulled the head today.

ABSOLUTELY do not use a Scotchbrite pad on a drill. I have seen those things wear (abrade) divots in IRON, they will tear up aluminum parts very easily. The abrasive dust left behind will take out the bearings; and I mean AFTER the guy thinks he's got all the Scotchbrite dust cleaned up.

I'll be trying "Goof Off" as a gasket remover, I suspect it will do the same job as the aerosol gasket remover spray at half the cost. If not...I'll buy the genuine gasket remover product.

My concern is that it may be that the gasket popping also created--or was created by--a low spot on both the head and block.

[mhildebrand]

When I replaced my head gasket, I used a carbide scraper to get as much off as possible, then i used some lacquer thinner on lint free rags and wiped it down, and then used the carbide again, I did this till it was clean.

[95 vert]

I use an air powered high speed (25k rpm) grinder with a scotch brite disc. I've been a dealership Mechanic
for years and have NEVER had a single issue. Used properly, it works great. Iron or aluminum.
I estimate I've done somewhere in the ballpark of 600 head gaskets. And even more intake and timing cover
gaskets, etc.

[carkhz316]

^Hmmm. Everywhere I read it says to never use any kind of surfacing disk on aluminum because of aforementioned reasons (the dust that destroys bearings). Every HG job I've done, I've just carefully: brake clean, razor blade scrape (carefully, so as to not gouge sealing surfaces), wipe with rag and brake clean, then repeat. It has always worked for me. Sometimes, there's what seem to be stubborn "stains" left behind, but it has never caused issues. Last job was the top-swap on the Monte and 5K miles later it's still purring.

[Schurkey]

I use an air powered high speed (25k rpm) grinder with a scotch brite disc. I've been a dealership Mechanic
for years and have NEVER had a single issue. Used properly, it works great. Iron or aluminum.
I estimate I've done somewhere in the ballpark of 600 head gaskets. And even more intake and timing cover
gaskets, etc.

Oh, sure...it's common to use the scotch-brite "cookies". I first saw them in '84 at the Chevy dealer I was at.

I've also seen the results as proven by the head surfacer at the machine shop: Aluminum worn away leaving low spots. Iron worn away leaving low spots. Success is reliant on the gasket being able to seal on non-flat surfaces.

Industry standards are going AWAY from scotch-brite gasket removers due to issues with silicon carbide contamination of engine internals.

But, yeah, they do make fast work of gasket residue. I've got a bunch of them in my tool box along with the velcro-faced mandrel...that have been un-used for fifteen years or more--ever since I saw a head go through the surfacing machine, making the low spots visible as untouched metal vs. the freshly-ground metal of the rest of the gasket surface.

[95 vert]

Oh, sure...it's common to use the scotch-brite "cookies". I first saw them in '84 at the Chevy dealer I was at.

I've also seen the results as proven by the head surfacer at the machine shop: Aluminum worn away leaving low spots. Iron worn away leaving low spots. Success is reliant on the gasket being able to seal on non-flat surfaces.

Industry standards are going AWAY from scotch-brite gasket removers due to issues with silicon carbide contamination of engine internals.

But, yeah, they do make fast work of gasket residue. I've got a bunch of them in my tool box along with the velcro-faced mandrel...that have been un-used for fifteen years or more--ever since I saw a head go through the surfacing machine, making the low spots visible as untouched metal vs. the freshly-ground metal of the rest of the gasket surface.

Again, never an issue. Some of the heads saw machine shops. Still, no issue.
I could see a possible issue if somebody ground the shit out of the surface.
Again, used properly-no issue.
And BTW, Industry standards have been "going away" from scotch brite discs since the early 90's.
I did head gaskets on my personal vehicle 100,000+ miles ago. I used SB "cookies" to clean the
surfaces. Still runs fine with 40 psi oil pressure at hot idle. It has not had any internal repairs done.

[GnatGoSplat]

I had the heads professionally cleaned/decked at a machine shop for this very reason, but I had a friend at O'Reillys so it got done for free (no idea the regular cost).

For the block, I think I used a lot of different things - plastic putty knife, a brass wire wheel on a Dremel, brass ice scraper, green scotch brite, and a brown abrasive disc that had no metals in it. The block was super difficult to clean due to some caked-on clay type deposits from Prestone Stop Leak I used years earlier. I don't know of any one thing that worked real well, I mainly just had to put in a helluva lot of elbow grease into it. I literally spent my afternoons for 2 weeks working on that block, trying to get it clean enough to eat off of. Seems to have paid off because that HG job was 13yrs ago and still holding up.

I once helped a friend replace the HG on an 80s Mercedes E-class 4-cyl. He refused to do more to clean the block and head than wiping it down with a cloth. I told him he should really spend some time getting that thing super clean. "Nah, I think it'll be fine." So he gets it all back together and big surprise, NO COMPRESSION! He ended up having to sell the car cheap to someone who would fix it right. Definitely very important to get it as clean as possible.