Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
209 Posts
Discussion Starter #1
I have a recently purchased Euro 1300 Super with the thermostat screwed into the intake manifold. I am going through the cooling system - the radiator came out and went to be cleaned this morning, water pump squeaks, so it goes next, etc.

When I removed the upper hose I found a mess of corrosion that has frozen the screw in thermostat in place. I've tried channel lock pliers, and PB Blaster and a pipe wrench, but it ain't moving.

Does anyone have a suggestion on removing the thermostat? I'm considering a torch next, but hesitate to use one because the engine is still in the car, with the fuel lines in place.
 

·
Premium Member
Joined
·
581 Posts
The electrolysis between the dissimilar metals can create some brutally tough bonds.
Heating the manifold with a heat gun might be enough. If you are replacing the thermostat, and the PB Blaster/pipe wrench doesn't work, consider cutting it out :( That's all that's worked for me in some intake manifold fittings that appear permanently corroded in place.
Drill out the center so that you can get a hacksaw blade in, then cut outward without cutting into the aluminum (actually since trhe t'stat is captured inside the hose, even if you nick the manifold you're not creating a leak path). Do that in two places an inch or so apart, then hit that section sideways with a chisel (at a right angles to the saw cut) to see if you can break out a wedge. once you've done that, work your way around the perimeter with the chisel and keep hitting it at right angles. The idea is to remove enough material in the first wedge so that the fitting/thermostat/whatever now can be displaced inwards away from the aluminum. You are NOT trying to get the chisel in between the t'stat and the manifold, you are hitting the protruding part of the fitting at right angles away from the aluminum toward the center of the hole.
To say the least, this is a last resort, but it has worked successfully for me over the years to rescuse some othewise good manifolds.
Wil Painter
 

·
Registered
Joined
·
1,260 Posts
LOL!!!! I have the same problem!!! :)
Is there something to put on the threads that will prevent this?
Thanks for the tip Wil

Cheers
Sprintn
 

·
Registered
Joined
·
209 Posts
Discussion Starter #5
Wil,

Have you ever tried that with the manifold still in the car? I really don't want to pull it out, but I can't imagine that brass filings are good for the cooling passages.
 

·
Premium Member
Joined
·
581 Posts
Jim:
Nope.
So I'm just musing "out loud" right now. The brass is non-magnetic, so no easy magnet solution. But the opening is quite large, so you may be able to "sweep" out from the front. Put grease on a rag on a stick, wipe out and collect shavings. Then clean residual grease from manifold. You could also disconnect the heater hose at the back of the manifold, and reverse flow water from a hose. Relative to oil passages, water openings much larger, and brass filings small, so you may decide to accept the risk of what's left. Maybe you try in place, and, after cleaning, if you still see filings you're unhappy with, then you pull the manifold. There will be more detritus from the corrosion than from the filings, so you have to do some cleaning in any case. Sometimes getting it right means more dissassembly than you'd like. Don't know what more to suggest.
Good Luck
Wil
 

·
Registered
Joined
·
1,260 Posts
Will,
It worked out well for me! Thanks! That technique even worked well for removing the old rusted, corroded,and crumbling hose connections at the other end of the manifold without damaging the threads... to speak of anyway. Those hose connectors definately weren't budging!
Thanks for your help!
Quentin
 

·
Premium Member
Joined
·
581 Posts
Quentin:
Thanks for the feedback!
You're right, it is a good way to get those stubborn little hose nipples out as well. I went ahead and bought a tap years ago, so when I'm done with the removal, I can chase/clean those threads.
So glad it worked!
Wil
 
1 - 9 of 9 Posts
Top