Looking for Opinions/Help

[William_89]

So the past few days I’ve noticed my average fuel mileage has dipped considerably from what it was a month ago. My truck starts, idles, and runs smooth. Engine temp is pretty low even after a 30 minute drive to work, temp gauge only goes up about 1/4 of the way instead of about halfway like it used to. I can touch the valve covers and they are only warm to the touch. Same for the upper radiator hose, warm to the touch. I’ve also noticed that the engine seems louder than usual (like the fan clutch is staying engaged all the time) and kind of lugging sometimes. No check engine light on, I’m not sure where to start.

 

[stamp11127]

Couple of things come to mind, stuck on fan clutch and/or stuck open thermostat.

 

[William_89]

I think I’m just going to try swapping the thermostat first. Seems like the logical first step being cheap and easy to get to.

 

[Trainmaster]

Make sure you get the proper thermostat. Many auto parts chains will sell you anything that fits in the hole.

 

[William_89]

Lucky for me I have worked at one for the past 10 years, so no chance of that happening lol.

 

[bobmbx]

I think I’m just going to try swapping the thermostat first. Seems like the logical first step being cheap and easy to get to.

to check the thermostat, wait overnight for a cold start. Start it, then grab and squeeze the upper radiator hose. There should be no flow (you'll feel it or hear gurgling). if you do that means your thermostat is open when it shouldn't be.

 

[William_89]

to check the thermostat, wait overnight for a cold start. Start it, then grab and squeeze the upper radiator hose. There should be no flow (you'll feel it or hear gurgling). if you do that means your thermostat is open when it shouldn't be.

Well I have about 5 hours till I get off work and it’s only 40 degrees outside. I’ll try that when I get off, that should be long enough for a complete cool down.

 

[mquick5]

Sounds like low coolant, have you checked?

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[William_89]

Sounds like low coolant, have you checked?

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Checked that earlier. Overflow tank and the radiator were both full.

 

[crector080862]

I have a question do our radiators need to be burped I know I had a Corvette but if you didn't burp are we get trapped in there and calls it overheat and I had a truck that you had to be careful of that few years ago

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[William_89]

I have a question do our radiators need to be burped I know I had a Corvette but if you didn't burp are we get trapped in there and calls it overheat and I had a truck that you had to be careful of that few years ago

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I am not sure on that. But I’m definitely not having an overheat issue. I have a lack of heat lol

 

[Boostedbus]

I think I would start with the clutch fan. Check and see if it spins freely when cold and engine is shut down.If it’s locked up all the time it will make it run cooler and burn more gas like you described.

 

[William_89]

I think I would start with the clutch fan. Check and see if it spins freely when cold and engine is shut down.If it’s locked up all the time it will make it run cooler and burn more gas like you described.

I’ll give that a look before/when I fire it up after work. I was able to stick my hand down there this morning and it was spinning slow enough for my hand to rub on the blades easily

 

[William_89]

I don’t think the fan clutch is locked up lol

 

[William_89]

Changed out the thermostat and now she’s holding running temperature really well. Needle stays rock solid right before the center of the gauge. See if that fixes the fuel consumption issue tomorrow

 

[Munkiebunz3]

I'm 100% sure it will. Engine runs with a rich fuel/air mixture until optimal operating temperature is reached. If it's never reached you will burn significantly more fuel at all throttle positions.

 

[Boostedbus]

I’m glad you found the problem. Always start out with eliminating the obvious things first before throwing parts at it. I wonder if your loud fan like noise goes away now also?

 

[stamp11127]

How to work safe - stick your fingers into a running engine fan assembly. If your fingers stay intack the clutch is disengaged. If a banging sound accompanied with blood flying everywhere is heard, the clutch is stuck on. Head to the ER and stop by the auto parts store on the way.

 

[William_89]

Riding down the freeway this morning I averaged 20-21mpg at 70mph. As far as the fan noise it seems a bit more quiet. Maybe I was just exaggerating that because I knew something wasn’t right. Held running temperature perfect the whole way to work so as of right now I think everything is ok. But I’ll find out over the weekend driving it around.

 

[William_89]

How to work safe - stick your fingers into a running engine fan assembly. If your fingers stay intack the clutch is disengaged. If a banging sound accompanied with blood flying everywhere is heard, the clutch is stuck on. Head to the ER and stop by the auto parts store on the way.

Works every time hahaha. On a semi serious note I made sure to “check the clutch” on the safer side of the fan rotation so my finger would just bounce off and not get smashed to bits. Definitely not a good way to do it but I’ve been in this for long enough to know when not to do something for safety reasons.