Volvo 1642GE Diesel Generator

Hello all
Hope you're well. I don't know if anyone can help me on this one but I thought I'd give it a try.
we have tow diesel generators that work together. One of these works about 4 hours and suddenly water temp goes up to 105 centigrade degree and connection of inlet water opens and system shows low water and high temperature and turns off.
pump and other equipments works correctly.
Could anyone tell me what is this ?!

Thanks Vawhid

Hello Vawid, welcome to the forum.

I'll give it a shot, but I need a little more explanation.

"connection of inlet water opens" do you mean it overheats and blows off steam? or is this generator cooled by a water heat exchanger instead of a standard radiator like a car or truck has?

If it has a radiator, has it been completely cleaned so you can see through the whole thing?

The best way to diagnose overheating issues is with an infrared thermometer, take the temps of the inlet and outlet of coolant from the engine, while running normally and then when it's getting too hot. That give a good idea what's going on.

Dear Delmer,

Thank you for your attention.
This is picture inlet water tube.

This generator is worked about 20 or 30 hours, it is one the 8 generators that we bought from Volvo Power.
This problem only happend to this one.
The radiator is clean, because it is new generator.
I want to know what do you think about it ?
Yours sincerely

New volvo with 30 hours??? isn't this volvo's problem? Don't they have anybody in Tehran? and you're on your own?

Nothing in the red circle should leak under any circumstances. Are you sure that's where the coolant comes from? There should be a cap on top of the radiator, or that clear/white plastic tank that should vent pressure if the pressure builds too high. Have you tried tightening that stainless steel hose clamp with a screwdriver, not with a socket unless you have your daughter do it.

Make sure the coolant level is correct also, I would think that plastic tank has a mark for the coolant level, one for hot and one for cold.

There is no cap on the radiator top tank. The overflow tank is used to fill the cooling system. Volvo usually does a good job of purging the air from the system as you fill the system. As was mentioned, monitor the system with a heat gun and make sure your fan belt isn`t slipping from a bad tensioner.

hi all
Thanks for your attention.
We checked all the possible things and nothing goes wrong.last night we turned it on and it worked without any problem.
but in morning when you turn it on, that problem happen. that black tube is the inlet water to the radiator.
In that place, at noon atmosphere temperature is about 55 centigrade degrees. I don't think it is about atmosphere temp because the other one works perfectly in that atmosphere.

You're certainly getting close to the ambient temperature limit, but like you say, if you have 8 of them then you know what they should do.

I'll repeat, nothing in that red circle should leak under at any time. The picture is perfectly clear, that's a standard radiator and hose, with the air cooler hose below it, and the plastic reservoir in the top of the picture. The cap should relieve the pressure if it builds too high, not the hose clamp in the red circle.

This gets a little difficult to diagnose because it takes four hours to happen, but somebody is going to have to figure it out. Either the temp gets too hot and the green antifreeze blows out of the cap and then it shuts down. Or the antifreeze leaks out of that hose clamp slowly, and then it gets hot because the level is low, and shuts down. Or, I hate to say it, it could be the engine is running at the proper temperature and the head gasket starts leaking pressure into the cooling system causing the coolant to leak and overheat and shut down.

Have you verified that the radiator is clean and clear, the belts are tight, the coolant concentration is correct, the air flow is set up so that the radiator doesn't get recirculated heated air from itself or it's twin.

Thank you very much Delmer
I called Volvo dealer in Iran at the day I posted this.
Today they send someone for checking it.

Dear Delmer
The Volvo expert checked the generator this morning, as he said the inlet and outlet temperature only has 5 centigrade degree difference.
he is going to change the Thermostat and check the generator.
he said if it is not from the thermostat he should change the water pump.
I would appreciate if you tell me what do you think about this.

vawhid said:

The Volvo expert checked the generator this morning, as he said the inlet and outlet temperature only has 5 centigrade degree difference.
he is going to change the Thermostat and check the generator.
he said if it is not from the thermostat he should change the water pump.

Click to expand...

That's a good start to check the temperatures. The air temperatures going into and out of the radiator might also help. This might need to be done after running 3.5 hours. It's easier to diagnose a problem as it's happening, than when it's running correct.

Checking the generator end is also a good step.

The plan of changing parts starts logically enough, but it doesn't inspire confidence in your expert's abilities. Changing parts when you don't know what's causing the problem is not an expert strategy. I would want a mechanic who observes the problem and then makes a better guess as to what the problem is.

The thermostat is cheap, fast and easy to change, that's why he's doing that first. The 5 degree centigrade difference would tell me the thermostat is not the problem. The radiator is clean internally, but might not be cooling enough on the air side, because of hot air recirculating, or not enough airflow.

OF COURSE, I'm not there seeing what he's seeing. And I live in a completely different climate. I'm just saying what I think based on the little bit you've told me.

I had a Cummins generator that did something similar on a hot day. When it was very hot out and at full load the engine temp would slowly but surely creep upwards until it shut down. The field service mechanic worked with the engineers and observed low temperature drop across the radiator. They installed a different radiator that was engineered differently but the same physical size and the difference was night and day. This took over a year due to the intervening winter and cold temperatures. But they allowed warranty on it even though warranty period was officially closed when the final repair was done because of the ambient temperature situation.

Dear Delmer
Last night the Volvo expert opened the radiator and brought to their central workshop for testing.
Please send me if you have any question about the generator that help to find out where failure happen.
Is it possible the other parts failure cause this problem ?!

Birken Vogt said:

I had a Cummins generator that did something similar on a hot day. When it was very hot out and at full load the engine temp would slowly but surely creep upwards until it shut down. The field service mechanic worked with the engineers and observed low temperature drop across the radiator. They installed a different radiator that was engineered differently but the same physical size and the difference was night and day. This took over a year due to the intervening winter and cold temperatures. But they allowed warranty on it even though warranty period was officially closed when the final repair was done because of the ambient temperature situation.

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Dear Birken Vogt
I see your answer now but last night the Volvo expert opened the radiator for testing.
Thanks for your attention.

Dear all
Volvo's central workshop called us and said what happened to the generator.
The radiator coolant that they used at first was expired and the radiator silted up.
They are going to fix it.
Thanks you for your attention.

Thanks for the update.

A silted up radiator sure could cause your problems. In a million years, I would never have guessed that bad antifreeze in a new generator of this size and quality would be an issue. Is there any silt in the clear plastic tank in the picture?

Please let us know how it turns out.

Dear Delmer
I don't think there was any silt in the clear plastic tank,because if it was there our operator or technician would saw that.
Could engine water path silted up too ?!

Sounds fishy... if it was a US manufactured engine I would suspect casting sand was stuck in there and came loose after the engine ran at load long enough to get everything hot.

vawhid said:

Dear Delmer
I don't think there was any silt in the clear plastic tank,because if it was there our operator or technician would saw that.
Could engine water path silted up too ?!

Click to expand...

Yes, if the radiator was silted up, then the engine should be flushed with distilled water a couple of times, or until it comes out clean.

I agree, it sounds fishy. Obviously this is not a cheap little generator, I can't imagine why there would be anything but the best coolant used, and I don't think any SCA coolant would drop silt, much less the newer formulas. Maybe the coolant concentrate was mixed with tap water? very bad tap water.

Delmer said:

Yes, if the radiator was silted up, then the engine should be flushed with distilled water a couple of times, or until it comes out clean.

I agree, it sounds fishy. Obviously this is not a cheap little generator, I can't imagine why there would be anything but the best coolant used, and I don't think any SCA coolant would drop silt, much less the newer formulas. Maybe the coolant concentrate was mixed with tap water? very bad tap water.

Click to expand...

Dear Delmer
Today the Volvo expert brought back the radiator and connect it to the engine, but as you said that it sounds fishy the problem didn't solve.
and after 2 or 3 hours the generator temperature went up and the same as before.
What do you think about it ?! and what happened to this generator?!the others work correctly but this one not.

Go back to post #7. I don't have any new ideas since then. Can you have somebody watch it run to see what it does first when it starts overheating? like in post #7. Or have an electrician take a look at the generator end and load compared to the others.

I was suspicious of silt in the radiator because it should have been very noticeable in that tank. You had the perfect shot of it. Plus you don't expect that in a new engine:beatsme

I'm surprised nobody but Greg has chimed in here. I'm not any kind of large Volvo diesel generator expert, just a jack of all trades. This shouldn't be that complicated though... Let us know what you find out.