1989 Turbo Van Overheats Quickly.

[Lugert]

Friend's van.

Takes about 60 seconds for the thing to get too hot, over 200 on an external gauge.

He has replaced the following already.
Waterpump
Thermostat
Radiator


Any ideas?

[Turbodave]

Headgasket? Exhaust gas getting into the coolant can pressurize the system, cause air locks in the thermostat housing and cause it to get hot. I would do a pressure test of the cooling system and see what the results are.

[Bardo]

dont drive it:thumb:
no j/k
check for air inthe system

[BIG PSI]

I had the same thing happen to RUBY. I changed the head gasket, the water pump, t-stat, drained and filled the cooling system, flushed the cooling system, changed the radiator,changed the head, it still was overheating. It ended up being a core shift in the block. Once I replaced the block the problem went away. The Mini would go from dead cold to 200 degrees in a matter of 3 minutes.

Chuck

[Lugert]

Chuck,

That sounds exactly like what this is doing.
This is a rebuilt block from a local shop, I was not really hoping to hear that.

Core shift? Like metal that has moved?

-Bryan

[3nglenn]

I doubt this is the problem: http://www.thedodgegarage.com/common_failures.html item #11 but worth reading. If it overheats that fast, like Dave said, sure sounds like a badly blown headgasket... Keep us posted. G.P.

[BIG PSI]

Chuck,

That sounds exactly like what this is doing.
This is a rebuilt block from a local shop, I was not really hoping to hear that.

Core shift? Like metal that has moved?

-Bryan

That is what happened to mine, they did a sonic test on the block and found it.
Junk one block. Before I crushed the MAHL's, RUBY would run 180 to 190.

Chuck

[Lugert]

Not #11, that has been checked.

I will tell him to try a HeadGasket, then talk to the engine builder if the problem is still there.

[3nglenn]

I had the same thing happen to RUBY. I changed the head gasket, the water pump, t-stat, drained and filled the cooling system, flushed the cooling system, changed the radiator,changed the head, it still was overheating. It ended up being a core shift in the block. Once I replaced the block the problem went away. The Mini would go from dead cold to 200 degrees in a matter of 3 minutes.

Chuck

Hmmm... Interesting. Core shift? Details on what that is...? Thanks

[Bardo]

WOW never nees that befor. i'd be pissed

[midohiomoparsource]

Could it be possible that when the engine was rebuilt, if any machine work was done, that metal got into a water jacket or two and plugged them up causing your overheating?

This is a new one to me, but I would like to hear the end result.

Matt

[5sp. mini]

just a idea is it the right water pump the 89 goes the other way than a 88 frist check part number then pump with old one,AL

[Garret]

Yeah I was going to see check the water pump, probably going around the belt instead of being ran off the backside of if, seen that done more than once on "rebuilt" engines when they get reinstalled

[87glhs232]

For those questioning core shift, it's a factory defect from the foundry when the block was cast. The sand core (mold) can shift slightly in some cases causing thin spots in the cast. When it's machined, even more comes out and it gets thinner. I've only ever come across 1 block (chevy 350) that had confirmed core shift. Sonic testing will be able to identify this.

Heres a link to a pic of a block that had core shift. It's a 350 and what your looking at are the lifter bores. Notice they're drilled offset on the bosses?
http://www.sporttruck.com/techarticles/1498/index4.html# (http://sporttruck.com/techarticles/p28832_image_large.jpg)

[boost geek]

I've had huge overheating problems in a s.c. which ended up being the heater core clogged solid. For some reason it would'nt let the thermostat open. I would blow it out, would eventually clog again. I put in a new aftermarket core, now it almost runs too cold with a 180 thermostat.

[3nglenn]

For those questioning core shift, it's a factory defect from the foundry when the block was cast. The sand core (mold) can shift slightly in some cases causing thin spots in the cast. When it's machined, even more comes out and it gets thinner. I've only ever come across 1 block (chevy 350) that had confirmed core shift. Sonic testing will be able to identify this.

Heres a link to a pic of a block that had core shift. It's a 350 and what your looking at are the lifter bores. Notice they're drilled offset on the bosses?
http://www.sporttruck.com/techarticles/1498/index4.html# (http://sporttruck.com/techarticles/p28832_image_large.jpg)

Thanks Josh. Good info.

[daytonajesse]

Does your rad get hot?
Try pulling the thermostat and running without just to see if it still stays that hot, I've bought new ones that died within a week, at least 2 times.

[Tony Hanna]

Does it seem like it's actually running that hot or just the gauge reading that way? It could be an air pocket or a steam pocket caused by a hot spot insulating the area around the temperature probe from the coolant. If it's the hot spot/steam pocket issue, something that lowers the surface tension of the coolant like Water Wetter or a little bit of dish soap (both are surfactants) will help by making it easier for the steam to dissapate.
HTH,