Cooling system questions

[Brockflock]

Hi All:

99 D1, 138k mi. Heads redone at about 128000 (about 2 years ago).

In the past 6 months, I have noticed that in hot weather, the temp gauge is a little higher than normal, but not anywhere close to overheating. Now it's winter in the northeast, and the temp doesn't come up to normal as quickly as it used to 9even for winter). Last night, on my way home from work, the needle didn't hit the normal range . I checked coolant this morning and the reservoir was low. I am not getting any white smoke in my exhaust, see no puddles on the floor of my garage or where I park at work. And I don't see evidence of leaks at hose ends, nor near the heads. And I don't smell anything in the cabin that seems like a leak from the heater core.

Is it possible I need a new thermostat and I have another problem as well? What do you guys think?

Thanks.

 

[listerdiesel]

You shouldn't need to top up more often than 6 months or so to a year, and while I do overfill my D2 reservoir by 1/2", I have topped it up once since May 2013, and that's what I'd expect to see.

Topping up means 1/2" of fluid to bring it back to my raised level. If I found the reservoir was low I'd be looking for the reason why.

Mine takes a while to get up on the gauge (gage) but 1 mile or so will have it just off the stop in freezing weather, 2 miles or so it is where it normally sits.

I have a gas vapouriser (LPG vaporizer) in the heater circuit which loses me a bit of heat early on, but it comes through hot eventually.

Peter

 

[Tugela]

First, you should consider buying a scan tool that displays live engine data. Something like a Turbogauge can be had as cheaply as $60 on the ebays. The dash gauge on the does not show engine coolant temperature with the level of precision that a diagnostic computer does. The temp gauge is just there to tell you you're screwed when it's already too late.

Second, you could have a cracked block. You could be burning coolant, which would explain why you can't find signs of a leak. Another way to test this is to buy a kit from an auto parts store that checks for combustion gases in your coolant. These usually go for about $30-$40 bucks. Also check if your coolant system is pressurizing. After driving around for a while feel the upper radiator hose and - if you dare - put on an oven mitt and slooooooowly open the coolant reservoir. If you hear air escaping like when you open a bottle of soda that's been shaken, you know it's pressurizing, which can suggest a cracked block.

Third, your head gasket could have failed again, but if you did the job right and resurfaced the heads then this is unlikely.

There may be other possibilities I am missing.

 

[Brockflock]

If I had a cracked block, wouldn't I have white smoke coming from the exhaust, or would I have some sign of coolant in my oil?? Other than that, I will give it a try with the kit you mentioned.

Thanks.

 

[mike97d1]

You should get an ultra gauge and find out what the temp is really doing. If it's not getting up to temp, I would think the thermostat would be a good start. How old is the current thermostat?

 

[bigcheif]

I agree with Mike. check your t-stat, even if it's not real old
shit happens!