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Hello,
I have a 89 dynasty 3.0l with about 180k on it. It has had little in terms of repair history other then transmission repairs and usual brakes and such.
Over the last few weeks it has been running very warm on long drives.
This week while on a drive home from work (approx 90 minutes highway with intermittant stops and some hills) the temperature sensor hit the max.
Thinking it was a thermostat issue that has been replaced (the original was actually broken in 2 parts). The issue remained.
THen went on to look at fluid levels. There appeared to be a fluid level issue so topped up the rad, ran it till the thermostat opened and topped it off again.
THe rad cap has also been replaced.
There was a small leak in the top rad hose near the connection to the rad that seems to be corrected by tightening the hose clamp.
Radiator and system were drained, flushed (a prestone cooling system flush was used) and new coolant/water added.
the vehicle was road tested for an hour yesterday in mild weather, above freezing temperature. No problems presented themselves. It ran with temp gauge in the lower 1/3 except at stops when it might get to half if the fan didn’t kick in right away.
Heater was working normally.
oil is normal, no evidence of water in it.
The radiator itself is in sad shape. Several sections of the fins are missing. No apparent flow blockages.This morning we had some frost on windows.
Started car as normal and let it run a few mins.
Drove from home and vehicle temp guage went to high within about a km of home. Fan appeared to be working, resevoir is little more then max, no evidence of a leak.
THe temperature fluctuated quite a bit during this trip. There appeared to be no heat coming from the heater.I’m wondering if this is completely due to the poor rad condition or could it be something else? Air in the system? I did attempt to bleed the air when doing the flush and fills.
I did notice some foam in the resevoir this am. Could the chemical flush be causing problems?
The hoses appear in good shape, the rad cap and thermostat are new. The coolant level appeared normal. The water pump seemed to be working fine yesterday. There is no obvious leaks.
There was some white smoke coming from the exhaust when the vehicle was cold but once it warmed up this seemed to disappear. I took this as normal.any ideas?
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Could be a bad head gasket causing an internal leak in the engine. Notice any funny smells at the tail pipe?
Could also be a bad water pump. Has it has ever been replaced?
A radiator in poor condition probably does not help but I doubt it is your issue, knowing your car still overheats on the highway.Is it possible your water/coolant mix is freezing. I’ve seen the same thing happen to a car were everything froze just enough to block the system but nothing busted so it didnt show any signs.
if your seeing foam.you didn’t get all the flush
out.you may need to flush the system again with
water.refill and re bleed the system.I’m going to
suggest a new radiator so it does not blow and leave
you stranded.;)Evidently this all started with a bad thermostat, that you describe as broken in two pieces. I’ll guess that your current problems are due to trapped air, ie inadequate burping.
The story of no heat from the heater suggests inadequate flow, either due to trapped air (most common), or perhaps a failing water pump. What sways me against the latter diagnosis is the fact you already found a clear cause for the initial overheat, and you also point out that water flow seemed to be OK. If there is any concern about failure to maintain pressure you could do a pressure test on the system and maybe replace the cap. But as a starting effort I would repeat the flush and then burp the system again. If all that fails I would broaden the net with a check for combustion gasses in the cooling system. Good luck.
Thanks for the replies guys.
Freezing coolant is unlikely to be the cause as this was occuring in above freezing weather.
Hoping it isnt a head gasket 🙁
Is there a bleed valve on the 3.0l engine for the dynasty? If so where is it. Was looking but can’t seem to locate it.
Water pump to my knowledge has not been replaced but seems to be working ok.
System also seems to pressurize well with no obvious external leaks.
Cap has already been replaced.As added info. This am after it cooled i looked at the resevoir and about half the fluid that was there in when warm was gone. I also had to add about a liter of fluid to the rad. There seemed to be air trapped in the top rad hose.
This seems to confirm an air issue?
If someone could tell me where the bleed valve is (if there is one) that would go along way.Thanks again.
+1 to the above video’s.
If you suspect a head gasket, i would use a block tester to see if there is combustion gasses in your coolant.
Also pressure testing the cooling system will be a good idea, again all shown in those video’s above.
Keep us posted.
[quote=”ace8489″ post=40720]Is it possible your water/coolant mix is freezing. I’ve seen the same thing happen to a car were everything froze just enough to block the system but nothing busted so it didnt show any signs.[/quote]
+1
Update,
Today vehicle started normally although there was a little bit of knock (thought maybe a cylinder misfiring or just cold)
Drove for about 10 mins and no overheat. Let sit at idle for a further 20 mins, stayed at or near the lower 1/3 of heat guage.
Pulled out one of the sensors near the thermostat prior to all this to see if fluid was present and it came pouring out as soon as the plug was removed so block is full.
Had to add about 500ml fluid to the rad, overflow is still good.
Fan kicked in once heat got to about just below 1/3
Found out trans fluid and oil were low.
So far no overheat at all and no apparent leaks.
Exhaust did not have a sweet smell and was not white
heater seems to be working fine now.Looking back on this it may yet have been a coolant mix issue. This car apparently holds 9 litres of coolant and i only put about 4l of concentrate into it then topped off with water. Quite possible the mix isn’t quite right and it froze. at some point in the system.
Today seems to be running fine.
Gonna let wife drive it around town for now to see how it does before i take it on long commutes. Probably replace rad as well if all is going well.once again thanks for the help
This screams air in the cooling system. Don’t worry about the bleeder valve, it’s only there to make filling the system easier. Use the video that was posted to bleed the air out of the system and then recheck for your symptoms. Make sure you follow every step in the video except the part about the bleeder.
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