GD350 problems - new radiator capacity and engine cooling
Hello, my name is Antonio, from Portugal,
I've a GD350, replaced gasket, grinded head, pressure test and installed big aluminium radiator, almost 15L
The engine typically even in heavy loads does not get over 90ºc and typically nearby the 80ºc.
The problem is that cooling fluid in expansion reservoir disapears, if I top it to correct level it goes bellow level and wrning light is on.
If I open the cap and depressurizes it almost gets to the level.
I don't find any leak and I'm not sure if there is fluid into the cylinder head?
It runs quite well but now in the morning that start is a bit irregular, do you think is water inside the cylinder head?
The engine never get too hot.
Thank you
Antonio
Hello and welcome to the forum Antonio,
Would it be possible to post a picture of your new radiator? I am interested in its design, in particular the Header tanks.
My suspicion is that you are left with an air pocket in your system that compresses as the radiator pressure builds up.
My initial suggestion is to jack up the front of the vehicle as high as you can and fill the cooling system. Did you measure how coolant you have topped up in total? Alternatively fill up the system using these modern vacuum filling systems. Do see coolant freely flowing from the radiator's over flow pipe to the expansion bottle?
If there is water in the cylinder head, you would expect a plum of white smoke during start up.
Is your oil leval on the dipstick going up? If so definate head problem. Hopefully not.
Are you saying that when you remove the pressure cap on the reservoir, the fluid level returns to the correct level?
If so, then it sounds like the is an air pocket in the system. Is there a breather pipe comming out of the top of the new radiator? Are you turning the cabin heater to full on when driving? Is there any moisture around the water pump?
Sounds like you have a good engine if it runs at 80C
Yes, there is coolant in the overflow bottle and today I took the tube out and let it free to a water bottle to check it.
I would say that fluid is expelled by pressure and I don't see any typical contamination of fluid on oil or oil in coolant fluid.
We just copied the radiator and I did not think much about it, now I've the problem I've switched my brain....
Might be the water pump does not provide the necessary capacity to move all the air or we need am additional tube connection on the other radiator column? instead of one we might have two connected to each other?
The water pump is recent 2,3 yrs old and I might check it also and try to see if we can improve something.
I think it took 3 x 5L water fills... I'll check, now we have a lot of coolant... I'm not sure if water pump is able to move all fluid around.
BR
Antonio
Just to mention, part of the combustion process does produce some moisture or water in the exhaust so do not confuse this issue suspecting head gasket leak again. Keep the heater matrix dial turned to hot position on your next run to allow water to circulate the matrix, hopefully any air pockets will flow into the radiator.
When the engine has cooled own, pressurise the coolant simulating runing conditions. If there is an air pocket you will see the water level in the expansion bottle drop under pressure.
Should this happen, over fill the expansion bottle and when the system is under pressure again the over filled level may compensate to achieve the correct level.
You need not concern your self about the water pump flow, regardless of radiator capacity the pump is designed to flow water around the block and you have done nothing to alter the blocks capacity.
Do you get warm to hot air blowing through your heater vents when engine is warmed up? Any gurgling sounds from the heater matrix when driving and heater when temperature turned up?
Yes, I've the gurgling sounds and I've been running with hot air working and is quite warm, it works well.
After your note I went to run it on a inclinated plan, quite steep and some blurps on the expansion reservoir.
I agree I've done nothing to impove water crculation but I don't think we can do much about it.
I'm not sure what water pump do I have but is recent 2/3 yrs old and probably I'll check it.
Today I got over concern as the start-up in the morning was not as usual, very unbalanced and with some smoke but soon I steped on the gas pedal it start to run ok with the usual knock until it warms and become quite smooth.
I'm going to check the glow plugs to see if there is one that is not working.
I've recently checked the injector nozzles all except one is not ok, I'll have to change them.
I was preparing in April a trip to Morroco, which I did on a Toyota with the group but on the voyage I had a turbo failure, vehicle was towed to MB dealer and turbo repaired and all compression testing turned ok and no damage was found. After that 've been driving around but always with the water expansion reservoir expeling water to overfill bottle but now it is much more dramatic, before I could drive for a week and now it throws it away in 30 mins driving.
Re glowp[ug.
If light illuminates ok with ignition and goes out when car has started , they are fine.
If light illuminates after start up, a problem .usually just one failed.
What happens if you top up expansion tank, and just replace cap loosely so it can get rid of air, or wait until proper temperature, with heater on?
If I warm the engine with cap on and after I release it, if done properly and slowly no major event and we can leave it open.
After if I close it and go for a run, in 10-20mins under load it throws water out of the expansion reservoir.
That's what I've been doing, no success.
BR
Antonio
That does not sound good. Is there any way the heater matrix pipes could be wrongly fitted?
Have a block test done to the establish if combustion gases are leaking into the coolant system, If the dye changes colour, you definitely have a leak.
To test the water pump, blip the throttle to do a quick engine rev. Watch the water level in the expansion bottle drop a tiny amount. This water level drop is difficult to see, so you may have to repeat the test a few times to confirm a level drop indicating the pump works or not.
You can buy a bleed valve that taps into the top of the radiator and allows you to expel any trapped air. As already said this is best done with the front of the car in a raised position.
I've done all the possible purge with inclinated front, it is much better.
Whatever I do, the engine temperature never get's too hot, at most I get one tick over the 80ºC, which I believe is 90ºC?
I'll continue to purge, with hot open but I still get sometimes the blurp sounds inside the inside heat exchanger.
The only change I notice is a kind of unbalanced start in the morning, first 5 seconds, this is new, but as I step in the gas pedal it goes alright. This is new.
Is it possible I've water leak inside the cylinders?
Next week I'll test the cooling fluid for exhaust gas to see if there is any possible contamination.
Thank you
Antonio
Normally bleeding the G-coolant system is no bother but in your case I suggest a vacuum fill. The system is drained of coolant and with an applicator the system is vacuumed. At a turn of a tap, the whole system replenishes with coolant and hopefully your problem is solved.
Ok, this is my latest observations:
1) I've disconnected the electric auxiliary pump, because it's new but when I was chaging it the wires of the socket poped out of the socket so now I'm not sure if the polarity is correct (?) although the socket is idiot proof I might have change the wires in the socket..... if I did change the wires might be the pump is circulating in wrong direction?
2) I've now been observing what happens:
a) the coolant mixture now is very poor as I've been refiling with water and now is almost water.... very low percentage of MB cooling fluid...
b) When I rev up the water lever rises from level inside the reservoir until it reaches the top and start bleeding out.... when I rev down water level comes back to initial level, as it has thrown some water out let's say 3 fingers bellow level.
c) The temperature doing this process in the garage is always around 80ºC, I'm not able to get a temperature rise more than that.
d) in the road if I go full gas, engine temperature goes to 90ºC, or just a bit over the mark, but soon I reduce the gas it get's to 80ºC.
SO, to resume, it is this process of water level increase when I rev up - expeling water, go-down when I revdown, that in the end arrives to yellow indicator on the dashboard and fluid level goes down.
MIGHT be I've to put again MB additive to 50/50 proportion and then do the experiment again?
DO you think the auxiliary electric pump has a role in the problem?
What I see is when I have the electric pump connected I've a lot more bubbles in the expansion tank, if I umplug it, the fluid inside the expansion reservoir is more calm, no bubbles.
Please let me have your insight, as I think we might be near to some kind of diagnostic?
I would love to move away of compression leak in the head gasket again... but it seems we might take it out to see if there is evidence of compression leak or water intake in cylinders.
BR
Antonio
Ok, I was able to stabilize the fluid level in the expansion reservoir, so far. after being hot, and 10-15mins drive, at 80ºC as I accelerate the level is more stable, not much up and down as before.
What I have after engine is cold on the start is unstable start with a bit of white smoke, this is new.... I bet you antecipate I've water leakage into cylinders?
So I think in the end I'll open head again to check if all again?
BR
Antonio
Does your main top tube to radiator is with some high pressure, a bit hard or rubber soft ?
Mine is more on the hard side, is this relevant?
BR
Antonio
Hi everyone.
it seems problem is solved, although expansion cap was new, it was a 120psi and indicated for this vehicle is 140psi.
I've been now running in hot summer days in Portugal and the level mantains and no more expeled coolant.
Let's see how it goes.
BR
Antonio
Have you checked the thermostat to ensure that it is opening and closing at the correct temp?
Disconnect the electric cable going to the aux circulating pump until you have fixed the direction of rotation. A dc motor will reverse direction with polarity and the impeller will be designed to pump in one direction. I have a spare one, I'll check which way it spins
Yes, the thermostat is new, is 79ºC and is correct on the dashboard temp gauge.
I'm going to check the pump tomorrow also, to confirm the which way it's pumping.
Thanx
Antonio
It would be good if you can keep us up to date with this issue.
Fingers crossed for you...
It would be good if you can keep us up to date with this issue.
Fingers crossed for you...
I've now water intake in the cylinders, no doubt.
I think I'll have to buy a new head or a reconditioned one, please advise.
BR
Antonio
fit a om 606 engine, the 603 350 has a bad reputation
Just bought a complete engine 60397212003895.
Let's see how it goes.
BR
Antonio
Is that another 350 td engine?
Yes, 60397212003895 with 190 000 km, from an accident car.
Update, I went to check and there is water in the oil, as we do not have a temperature problem, we believe we might have a problem in one of the cylinder lignings.
It seems a sad end to this engine, let's see how it goes with new engine, it looks good.
BR
Antonio
Thats come out of another G350TD....lucky find
A 1995 Onyx Grey Belgium supplied vehicle
New (603.972) mounted, 190k.
At least now we can open the epxansion reservoir cap, no pressure at all, that's a good feeling.
Engine runs well, I've a bit o trouble with vacuum lines, the gearbox change is more harsh and it seems turbo is not giving it the full power.
Engine temp around 80, with full gas for some time around 85-90ºc.
So, I think in the good line of work.
BR
Antonio
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Hello to all, thank you for your kind help,
not really sure about white smoke in the morning and this is very recent behavior, but somehow today I think I got this impression today, a lot a dark dirt in the ground, almost humid.... like when we get some water in the exhaust.
I'm going to check it but might have a bad glow plug.
No water/rise level in oil stick or in the coolant.
Yes, I believe it might be air traped inside, I've place the car in inclined plane and I can hear a lot of noises inside the heat exchanger inside the car, as also the auxiliary pump works.
Whatever I do the temperature is at most a little bit on top of the 90ºc, but typically around the 80ºc or a bit above.
On idle and at home, I can be on the gas pedal, 2500-3000 rpm and temperature is always bellow 80ºc.
Regarding the radiator, we just copied the old one, bigger sides and took from old one that was 2 yrs old the inside exchangers, oil and auto gearbox.
BR
Antonio