engine running warm

[Alxsmt]

well im having a problem with my hybrid running warm. old cruise temp was about 206* all the time, recently it bumped to 216*. everything on the engine has about 25k on it. fan kicks in at 225* but its nolonger working (fan motor or relay is my guess but those were replaced with my last engine, noticed it died yesterday so I havnt checked it out yet). it has been a little warmer than I like to see due to the fan but not overheated.

im clueless on what caused the cruise temp issue, it has plenty of water/coolant. my guess is maybe the water pump? I just had 2 water pump issues in my other cars but those just flat out failed.

any ideas?

[kflo 93 gt]

Fix the fan and see where it goes. Otherwise, 25k on the coolant, not a ton of miles but replacing it with fresh wouldn't hurt anything - it could have some condensation build up in it. For the piece of mind that it's worth, the water pump is cheap and easy, even easier if you're going to replace the coolant.

How's the serp belt looking? Cracked or worn at all?

It all depends on how long ago the fan actually quit and when you noticed the rise in cruise temp. Step 1 is fixing the fan for sure.

[Alxsmt]

the coolant has been replaced a few times from tearing the car apart. how does condensation build up affect anything? the car get driven a few times a month at most.

can you tell a worn out water pump from a good water pump? I might pull it off in the next few weeks. The belt looks fine from what I remember but it is streched out, I completly forgot about that until you said that. Ill have to take a closer look at it this weekend, maybe its too loose for the tensioner..

why does it depend on how long ago the fan quit? thinking it got overheated and killed a LIMG? I noticed the cruise temp 2 months ago, but the car has been driven twice since then. hottest I saw it was 235* on the head, but the computer reads a little lower (different sensor).

thanks for the ideas! Ill update when Im able to check it out

[pocket-rocket]

Most of the time a bad water pump will weep coolant from the weep holes, but not always. Take the belt off, check it for play in the pulley. If there is ANY, change it.

[Alxsmt]

alright, I replaced the fan motor, relay, water pump and belt. the pump had a LITTLE bit of play, not much at all but it was there.. so far the temp stays right around 212 but its the hottest day of the year too. temp does wonder sometimes but I think I just have an air pocket. I also noticed one of my caps on the overflow (like a vacuume cap) was falling apart so the system may have not been pressurized, that got fixed too.

[beastberetta]

drop down to a 180 thermo like i did, crusing temps are 176.2 according to my elm scan 5 tool.

[Alxsmt]

I dont even want to think about pulling the front header off to do that lol. it has the factory recomended t-stat, seems like it was 190 but I cant remember. Ill see how it does in the next few days.

[pocket-rocket]

I remember reading two different things regarding engine temps.

1) Colder Tstats accelerate cylinder wall wear.

2) The hotter the engine, the more efficient it is (as long as it's not hot enough to damage parts). This is probably why GM sets the fan turn on temps a few degrees over 210 or so.

[robert 1980]

Yeah i think im going to reinstall a 195 for the 180 onces my engine is pulled

[Alxsmt]

yeah heat is horsepower. to an extent I guess.

anyways. I have been driving it all week.. the temp is still higher than I want it.. my fan isnt turning on.. Im planning on hooking the laptop up to see what the factory sensor is reading, maybe its bad and reading low? I have never even heard of that problem but its possable I guess? I got a new over flow "radiator" cap and that didnt affect anything.

this just doenst make sense to me