Turbo 3B Overheating

[01dakar650]

@01dakar650 what radiator is that? The upper hose is on the wrong side from normal 3B radiator setups.

It’s the stock radiator. I’m surprised no one else said anything, lol. I had the casting moved to the other side in an effort to ensure coolant is flowing through the entire radiator and not just part of it. May sound silly, but I did see a slight improvement, even though it still overheats.

 

[GTSSportCoupe]

It’s the stock radiator. I’m surprised no one else said anything, lol. I had the casting moved to the other side in an effort to ensure coolant is flowing through the entire radiator and not just part of it. May sound silly, but I did see a slight improvement, even though it still overheats.

That's really interesting you did that. I've thought of doing the same on my rad, as the in/out are on the same side also. I wondered if my going to a four core made it worse, as the coolant would have even less motivation to flow to the far side of the rad (with all those extra channels there). I never did get around to trying; but nice to hear it did make some difference for you (although not enough).

 

[01dakar650]

That's really interesting you did that. I've thought of doing the same on my rad, as the in/out are on the same side also. I wondered if my going to a four core made it worse, as the coolant would have even less motivation to flow to the far side of the rad (with all those extra channels there). I never did get around to trying; but nice to hear it did make some difference for you (although not enough).

Yeah I figured I’d give it a shot. Didn’t think it could hurt.

 

[iliketrucks]

I don't think timing alone would be the cause of your issue, but it's probably worth looking into after the head gasket is verified.

Diesel Timing Your Cooling System?

Online Diesel Community featuring news and articles on 6.2L, 6.5L and Duramax GM diesel engines, Ford Powerstroke, Chevy Cruise, lubrication and more.

www.maxxtorque.com

I've been pretty curious lately on the relationship between timing, egt, and coolant temperature.

 

[01dakar650]

I don't think timing alone would be the cause of your issue, but it's probably worth looking into after the head gasket is verified.

Diesel Timing Your Cooling System?

Online Diesel Community featuring news and articles on 6.2L, 6.5L and Duramax GM diesel engines, Ford Powerstroke, Chevy Cruise, lubrication and more.

www.maxxtorque.com

I've been pretty curious lately on the relationship between timing, egt, and coolant temperature.

That seems like an interesting article. I will check it out for sure. Thanks!

 

[Elfego]

Following here. I am having issues on my 1B engine on my 40.
Although, I have not installed EGT and Boost Gauge yet to troubleshoot.
I also haven't fully piped my front mounted intercooler.
Already changed the head gasket once.

 

[BreckenridgeCruiser]

Your B engine will produce even more heat than a 3B since it does not have the piston skirt cooling/oiling nozzles.

Boost gauge is optional, but EGT is not with a turboed B series engine. Unless you want to crack a head, you will not know you are overheating the engine until your coolant temps climb, which could be too late.

 

[Dougal]

Cold air intake is a necessary thing. You can add 30-50C to your intake temps by sucking on the back side of the radiator.

Pod filters are also absolutely terrible as filters.

 

[brownbear]

Okay I have a 100K on a 3B turbo. They don't run hot normally. They are a great engine, but maybe a bit boring for speed...

They do not need an intercooler. You should run about 10-12 psi max. No intercooler is needed. You cannot run higher boost due to the idi and precups so don't waste your money.

I used to have heat issues in the beginning. It takes a lot of burping on the system to get the air out. Any air will cause your overheating issue.

Run it with the cap off and let it burp. Clean up your coolant so no dogs die...

Do not run too rich on coolant to water. I had to dilute my coolant a lot and found it keeps much cooler with a higher water ratio. Use a hydrometer setting the coolant lower limits. Don't try for -40. I run about -25 -30 and never had it freeze. I live in the middle of Canada.

work hard getting the air out. This is a the first google hit I had on it.There may be better articles. But the premise is there. You could try to get a vacuum coolant tool. How To Bleed Your Cars Cooling System (9 Easy Steps) - https://mechanicbase.com/coolant/bleed-cars-cooling-system/

 

[Dougal]

Do not run too rich on coolant to water. I had to dilute my coolant a lot and found it keeps much cooler with a higher water ratio. Use a hydrometer setting the coolant lower limits. Don't try for -40. I run about -25 -30 and never had it freeze. I live in the middle of Canada.

This^^ is important. Glycol has half the heat capacity of water. Too much glycol can really hamper your cooling system.

 

[Darkwing58]

Yeah you’re right about the intercooler. It’s a SMIC from a 2000’s VW. I don’t really have anywhere else to put it. There isn’t much room in front of the radiator, so there it went. It actually does a pretty alright job where it is. Even with the engine overheating the intake tube is barely warm.

Look at a intercooler from an Audi 740 should fit in front of radiator,

 

[Dougal]

I had to remove the stock air box to run the tubing for the intercooler, hence the cone filter. Exhaust, not sure what what I have even counts as exhaust. It ends about two feet from the exhaust side of the turbo. I have a new water pump in the box but I hesitate to install it bc the heater works great. And from what I understand, if the WP was clogged or not working then the heater would be blowing cold air, and not allow coolant to flow to the radiator. My radiator can cook an egg so I’m guessing it’s getting circulated coolant. Am I wrong about that? There is no oil leaking anywhere on the truck .

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Having a better look at this.

I see a hot air intake.
I see an electric fan with no shroud. That will just stir hot air around instead of drawing air through the radiator and engine bay.
I see an intercooler on the wrong side of the radiator (interheater).

Ditch all of that. Put the factory fan and shroud back on the radiator. Ditch the intercooler (you're only running single digits boost right?) and get cold air to the intake.

Your cooling problems will all vanish.

 

[01dakar650]

While I’m sure all of that would help a little, I went ahead and removed the cylinder head and sent it off to be machined and magnafluxed. Turns out there are 13 cracks in the cylinder head. I don’t think any amount of air moving through the radiator or intercooler will help with that many cracks.

 

[Dougal]

While I’m sure all of that would help a little, I went ahead and removed the cylinder head and sent it off to be machined and magnafluxed. Turns out there are 13 cracks in the cylinder head. I don’t think any amount of air moving through the radiator or intercooler will help with that many cracks.

Were you having issues with air in the cooling system? 3B's and cracked heads are an iconic duo. I'd expect most to be cracked but not all to be leaking.

You need to have your cooling system sorted to prevent them recurring.

 

[01dakar650]

Were you having issues with air in the cooling system? 3B's and cracked heads are an iconic duo. I'd expect most to be cracked but not all to be leaking.

You need to have your cooling system sorted to prevent them recurring.

As I wrote in the first post, the radiator has been fully rebuilt. The thermostat has been replaced, the water pump works and I have a new one as well, and before I changed the mechanical fan, the fan clutch had good viscous fluid in it. At this point, there isn’t anything left but the cracked head leaking exhaust gas into the coolant that could be the problem. The engine was overheating with all the stock coolant components before I started changing things (ie, different air filter, electric rad fan, intercooler). Correct me if I’m wrong.

 

[Dougal]

As I wrote in the first post, the radiator has been fully rebuilt. The thermostat has been replaced, the water pump works and I have a new one as well, and before I changed the mechanical fan, the fan clutch had good viscous fluid in it. At this point, there isn’t anything left but the cracked head leaking exhaust gas into the coolant that could be the problem. The engine was overheating with all the stock coolant components before I started changing things (ie, different air filter, electric rad fan, intercooler). Correct me if I’m wrong.

Exhaust/air leaking into the coolant is obvious. The system pressurises, coolant is lost out the overflow and it keeps needing topup. If you didn't have those symptoms then your cracked head wasn't leaking.

Turbochargers add more heat to an engine. Hotter intake, hotter exhaust and more fuel is burnt meaning cylinders and head runs hotter and sheds more heat to the coolant. If you had anything wrong with a cooling system then a turbocharger will expose them.

Your current setup with a hot air intake into the turbo, no fan shroud and an intercooler on the wrong side of the radiator will all cause cooling issues.

 

[01dakar650]

Exhaust/air leaking into the coolant is obvious. The system pressurises, coolant is lost out the overflow and it keeps needing topup. If you didn't have those symptoms then your cracked head wasn't leaking.

Turbochargers add more heat to an engine. Hotter intake, hotter exhaust and more fuel is burnt meaning cylinders and head runs hotter and sheds more heat to the coolant. If you had anything wrong with a cooling system then a turbocharger will expose them.

Your current setup with a hot air intake into the turbo, no fan shroud and an intercooler on the wrong side of the radiator will all cause cooling issues.

All of those changes were made after the turbo was installed. I was absolutely loosing coolant out of the overflow, every time I drove the truck. I was swapping other components in different configurations because I was trying to avoid removing the cylinder head. Wishful thinking. As far as the modifications: I have a shroud for the radiator fan, it just wasn’t on in the photos. I bought a used intercoller at a salvage yard because I didn’t want to spend a lot of money on it because I was fairly sure it wouldn’t solve the issue. Since I was shopping used, I had limited choices on intercoolers, so I couldn’t find one that fit in front of the radiator width and length wise. Due to the limited space on the right side of the engine, I had to remove the original air box and replace it with a cone filter so I could route the IC piping. Either way, it’s not the final set up. I just wanted to have a filter on the truck while testing to see if it still overheated. I wanted to try an electric fan because I live in an area with a lot of stop lights and I don’t have relatively long distances for the fan clutch to stay at high rpm’s to cool the engine. So I wanted to try something that was at full rpm at a stop. It did actually help cool the engine down faster, but didn’t prevent it from overheating. Again, all of these things were done in an effort (maybe foolish) to avoid pulling the head and replacing it, if needed. Which it does need to be. 3B cylinder heads not cast in china, are not as common as my 351M small block.

 

[GTSSportCoupe]

Well, I suspected the head from the beginning, but sad to hear it's not something cheaper/easier to fix.

Any pictures of it that you can share with us?

 

[Diesel Cruiserman]

Well, I suspected the head from the beginning, but sad to hear it's not something cheaper/easier to fix.

Any pictures of it that you can share with us?

GTSport is the OG when it comes to 2lte and other pre cup diesels,, reading back through I would of done a radiator pressure test and listened for air escaping. What we use to do at Radd Cruisers was warm the engine up and once up to temp we would rev it up and watch for bubbles in the radiator, easy quick indication.

This would be a great time to throw in some new precups, deck the heat and use a OEM head gasket. Pretty hard to completely ruin this big cast iron head, should be fixed easily. I am currently doing a full 3B engine rebuild, two of my doubled up valve springs were broken so I replaced them all and put in new valve seals.

 

[01dakar650]

The machine shop I took it to said some of the cracks were too deep to repair. There is a crack in between the intake and exhaust valves on each cylinder, and each pre-combustion chamber seat has two cracks except cylinder four which has three.

I bought a set of new pre cups from Radd Cruisers but I found a complete rebuilt head at 4 Wheel Auto Wholesale in Edmonton.

It’s hard to see the cracks in some of the pictures, but the shop brought me in the back and re-did the magnalfux to show them to me. The cracks in the pre-combustion chamber seats start vertically in the seat itself and work their way down to the horizontal surface where the head gasket would sit. It was easy to see them when magnafluxed…below are a few picture of the ones you can see without mag.