No heat after warm up, well almost.

[movado750]

So I left the 06 m35 outside the last couple of nights and went to go warm it up for 10 minutes first night and got in it and no heat. Started driving and nothing till about 3-4 miles down the raod and then turning it off and on a couple of times it turned on. Same thing this morning but this time I let it warm up for20 minutes thinking last night the engine must not have gotten warm enough for the computer to start the blower.

Iti did finallly start blowing after five minutes this morning, but I was cold for the first five minutes really annoying since it is going to be outside the rest of the winter.

I understand that these things will not blow hot air until the engine is warm but this morning the enigine was plenty warm, right in the or just below middle on the gauge.

any help would be great.\

[splix]

Check your coolant level, it sounds like its low.

[movado750]

Just went and checked and about a minute after i started it the fan kicked. Temp was less than a quarter.

So ummmm. Relay or a sensor. Radiator all good never leaks anything. She does have a 173k.

[myother45isalesbaer]

Just went and checked and about a minute after i started it the fan kicked. Temp was less than a quarter.

So ummmm. Relay or a sensor. Radiator all good never leaks anything. She does have a 173k.

Could it be as simple as a bad thermostat?

[movado750]

well woke this morning to 10 degrees outside. Started M35, let warm up for 25 minutes, got in her nothing no heat. Everything was on temp set at 75, on defrost. Drove 12 miles and then she finally turned on high with hot heat.

I have had car with a bad thermostat and they would get warm while sitting there not moving but as soon as you would start drivng the engine would loose heat and start blowing cold air.

Granted this was on a 87 prelude many years ago with no climate controll or air sensor.

Am I missing something here. is it kind of back wards that the engine is not gettting hot enough because the t stat is stuck open so the air temp sensor will not get hot enought to blow hot air untill it gets really warm.

I will change the t stat and see if that resolves the problem.

Anyone done on a M before? I have not even looked to see where it is yet.

Any help would be great...

Miles

[myother45isalesbaer]

well woke this morning to 10 degrees outside. Started M35, let warm up for 25 minutes, got in her nothing no heat. Everything was on temp set at 75, on defrost. Drove 12 miles and then she finally turned on high with hot heat.

I have had car with a bad thermostat and they would get warm while sitting there not moving but as soon as you would start drivng the engine would loose heat and start blowing cold air.

Granted this was on a 87 prelude many years ago with no climate controll or air sensor.

Am I missing something here. is it kind of back wards that the engine is not gettting hot enough because the t stat is stuck open so the air temp sensor will not get hot enought to blow hot air untill it gets really warm.

I will change the t stat and see if that resolves the problem.

Anyone done on a M before? I have not even looked to see where it is yet.

Any help would be great...

Well, yes you are kinda missing something. The stat stuck open lets the cold coolant flow and too fast so it does not hold it back and let the coolant heat up. As you drive the engine throws off more heat the stat needs to slow it down so it has time to cool in the radiator. An open stat can actually cause a no heat when the engine is cold and an overheating condition when the engine is hot. Unfortunately I don't know where mine is either, so I can't help you there.

Miles

[movado750]

Yeah I get the whole t stat deal, but it never overheated this summer, might have just happened closer to winter. I will dig into into tonight and replace the t stat.

Thanks,
Miles

[M35 Sport]

You either have low coolant, a bad T-stat or both. With 173K miles the t-stat is probably the issue. It probably failed in the open/safe position so that the car does not over heat. That is what they are designed to do.