what is the max water temp i can run without warping the head.... to all who have numbered gauges... i hit 210 degrees last night... i dont know what normal operating temp is...
Max Water Temp...???
- Thread starter headlightwashers
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thanks... uhhh i think that means i need to get the fan shroud... cause it did it when was just sitting there for 20 min.... thanks...
For my Volvo that has an OBD-II port, if I look at the engine coolant temperature (ECT) as I drive around it varies from 190F to 220F all the time. I think 220F is when the electric fan kicks in. Typically on the highway it runs 190-195 F (it has a 190F thermostat). In town with less airflow it can easily go up to 220+F on a hot day with the A/C on. With 50:50 coolant and 14psi cap you should not boilover until about 265F.
I ran in the 200-210 regularly and hit 240+ on mine with no permanent damage. It got to the point that the ecu started pulling timing and the engine started missing. Of course that was with NPG+ coolant (don't ask me what I think of that crap).
I have a quick question: When I'm driving, my water temp. fluctuates between 190 and 210 or so. But as soon as I park the car and shut off the engine, I noticed the temp climbs to about 230, fluctuating +/-5. I'm guessing it's because the coolant gets hot from the engine, and the water pump's not running, so the hot coolant shows high temps. I'm just wondering whether this is normal. I guess I'm paranoid of reliability, and a BHG.
Max temp really isn't the factor you need to worry about anyhow. The reason heads warp is because people run out of coolant - usually due to excess pressure. Too much pressure will force coolant out of the overflow - lose too much coolant and the temp will climb by a huge amount.
Pressure is caused by all kinds of things, but primarily BHG firing combustion gasses into the coolant jacket or overheating way past the boiling point.
And of course, the boiling point depends on what kind and mixture of coolant you are using.
Pressure is caused by all kinds of things, but primarily BHG firing combustion gasses into the coolant jacket or overheating way past the boiling point.
And of course, the boiling point depends on what kind and mixture of coolant you are using.
Well said Grim. If the coolant system is healthy then coolant should run slightly above the T Stat rating and never below. To address your problem in another thread, the only reason coolant flows into the overflow bottle is because system pressure exceeded radiator cap pressure. That can only happen by not removing the heat load (thereby raising the boiling temp) or by adding to it ie; low or coolant not circulating, plugged radiator (internal or external), bad fan clutch, ect. A leak can also reducing pressure and raise boiling point. Additional heat load and pressure is almost always caused by a combustion leak.
I see 210 routinely sitting in 115 degree rush hour traffic heat, soon as Im rolling everything is cool. BUT I have a mechanical gauge and I am POSITIVE my gauge is correct. Hell you can see when the thermostat opens for the first time in the morning. Electrical gauges scare me.
The phenomena of the temp rising on a recently turned off motor is called "heat soaking", you will notice (give it about 5 minutes or longer) firing the engine up again for a second or two will circulate all the cool water in the radiator into the block and the temp will drop a bunch. I do this at hot autoX events here in phx.
The phenomena of the temp rising on a recently turned off motor is called "heat soaking", you will notice (give it about 5 minutes or longer) firing the engine up again for a second or two will circulate all the cool water in the radiator into the block and the temp will drop a bunch. I do this at hot autoX events here in phx.
And......if you are pushing coolant into the overflow bottle (usually BHG), especially when cruising down the highway, the level in the engine will go down. What happens is the temp gage may NOT rise. This is due to the fact that it takes coolant to be on (touching) the sender for the gage to work properly. Hot air/steam will usually keep it just below 1/2.
What will happen is ....when you slow way down or stop (like a stop sign), the temp will spike up, because the VERY HOT coolant will surge/boil up and touch the sender.
If you ever notice your gage (and who doesn't keep an eye on it in a MKIII) fluctuating up and down while you're driving along, then it is very likely your coolant is low in the engine. The coolant is not touching the sender full time like it's supposed to.
NOTE...The low coolant warning light will NOT come on because the bottle is full (of overflowed coolant).
The best thing to due is get to a water hose quickly, let the engine idle, hood up, and soak the radiator for a few minutes. This will cool the coolant down, and the engine. Use a rag to protect your hand, and slowly open the radiator cap to the first position (this position will not allow it to blow off).
Keep the hose water flowing on the radiator. Now remove the cap, and slowly add water to the radiator, till its full.
NOTE...be careful of hot steam. If it is still steaming alot, you probably have very little coolant left in the engine.
If it seems like its just steaming away, it may be too late to save it, and probably not a good idea to continue driving it.
The above senerio(?) happened to me 3 times on long (2-4hr) trips. I finally replaced the headgasket a few months later.
What will happen is ....when you slow way down or stop (like a stop sign), the temp will spike up, because the VERY HOT coolant will surge/boil up and touch the sender.
If you ever notice your gage (and who doesn't keep an eye on it in a MKIII) fluctuating up and down while you're driving along, then it is very likely your coolant is low in the engine. The coolant is not touching the sender full time like it's supposed to.
NOTE...The low coolant warning light will NOT come on because the bottle is full (of overflowed coolant).
The best thing to due is get to a water hose quickly, let the engine idle, hood up, and soak the radiator for a few minutes. This will cool the coolant down, and the engine. Use a rag to protect your hand, and slowly open the radiator cap to the first position (this position will not allow it to blow off).
Keep the hose water flowing on the radiator. Now remove the cap, and slowly add water to the radiator, till its full.
NOTE...be careful of hot steam. If it is still steaming alot, you probably have very little coolant left in the engine.
If it seems like its just steaming away, it may be too late to save it, and probably not a good idea to continue driving it.
The above senerio(?) happened to me 3 times on long (2-4hr) trips. I finally replaced the headgasket a few months later.
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NDBoost
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werd, and if your not careful (like me) after putting the overflow bottle right next to the battery the hose that feeds into the overflow from the radiator was literally sliced in half by the belt.mrnickleye said:
This caused air to somehow leak into the system and make bad things happen. Didnt blow the HG luckily because i pulled over and did what mrnickleye said to do. Run cold water over the radiator until it kinda stops evaporating off the radiator, pop the cap and fill er up let her sit a bit more and continue spraying water on the radiator and upper hose area.
Also if you turn your key to ACC the electric fans will come on (at least in my 91) and you can cool the car off w/out it running.
edit:
forgot to add, as soon as you see that temp gauge spike roll down your windows and turn the heat on full blast as your pulling over. Leave it on until you get the water back in the radiator and are driving again.