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Discussion Starter #1
Alright, I've checked the head gasket and all is welll and good. Thanks be due to the fact I replaced the darned thing less than a year ago. ANYWHO, she usually runs just at the halfway mark on the gauge. However, shes intermitently running up to the 5/8 line. Typically this will happen on a hot day, but if she idles too long the temp will go up. The seal on the water pump needs to be replaced due to a slow leak. However, I don't think this is all thats going on. In short, I don't think the fans are kicking on high. I did replace the fan sensor, but the same thing continues to happen.

I thought I might be dealing with flow, but the coolant is moving. On a side note, the blower for the AC is acting funny, but the overheating issue will happen w/ or w/o the AC running.

SO.... if I am dealing with a fan issue (no codes have come up), what is the next step? Also, is there something that I'm missing? Honestly folks, I'm at a loss here. I've put in an engine and a whole bunch of other goodies.... what should I do next?

Thanks

Jean:alchi:
 

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90 Eldo -SOLD-, 98 ETC -SOLD-, 86 XR4Ti Track Car, 07 Ranger
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963 Posts
1) Replace water pump, easy to DIY if you get the silly water pump tool...
2) Check thermostat/replace, cheap and easy to DIY
3) Check radiator cap is holding proper pressure/replace, cheap and easy to DIY
4) Check ALL radiator hoses, clamps, AND HEATER CORE for leaks/replace as necessary
5) Check the radiator side tanks for leaks/cracks, also inspect the drain valve (it's plastic and gives out over time)/replace radiator, not cheap but relatively straightforward DIY
6) Check radiator electrical connectors/motor may be bad, easy to DIY
7) When you/had the head gaskets replaced did you/they TIMESERT the block?

If you answered NO to #7, go have a dye test done on your coolant to check for the presence of combustion byproducts in your coolant...
 

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White Diamond '03 DHS (with DTS floor shift)
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Check the purge line. Do a search for it if you don't know what, where or how.
 

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Discussion Starter #4
First, thanks so much for the response. I'll answer the questions in order to streamline the details.

***1) Replace water pump, easy to DIY if you get the silly water pump tool...

The water pump has been replaced and checked. Yes, I did get that silly little tool. Matter of fact, I still need to take it back.

***2) Check thermostat/replace, cheap and easy to DIY

Done did it!

***3) Check radiator cap is holding proper pressure/replace, cheap and easy to DIY

Done did that too.

***4) Check ALL radiator hoses, clamps, AND HEATER CORE for leaks/replace as necessary

Yuppers... I did that :)

***5) Check the radiator side tanks for leaks/cracks, also inspect the drain valve (it's plastic and gives out over time)/replace radiator, not cheap but relatively straightforward DIY

Radiator has been replaced. Actually, I replaced it for the very reason you mentioned. Darned thing was leaking out the side ever so slightly.

***6) Check radiator electrical connectors/motor may be bad, easy to DIY

They have been checked

***7) When you/had the head gaskets replaced did you/they TIMESERT the block?

I had the whole engine replaced. When the head gasket was going out I was fortunate enough to overheat round abouts the same time. In short, I cracked the block to boot.

Ranger, I've been lurking around for a day or so and already checked the purge line. The hollow bolt has been checked as well.

Today we were tinkering around with it and the overheating seems to follow a bit of a pattern. Before all this started, the gauge stayed on the middle mark regardless of the outside temp. Since this drama ensued, it will go up almost to the 5/8 mark and then go back down. Mostly this happens if I'm sitting in traffic, but every now and again it will happen when I'm mobile. I do know the water pump seal needs to be replaced. I thought we had replaced it, but it's still sitting in the garage. I'll get very slow leak right where the water pump housing meets up the engine.

Our best guess at this point is something in the fan relays, but nothing comes up on the codes. We did hook it up to diagnostics and had the fans running on high, but aren't sure whether or not they're coming on while driving. If I'm idling (w/ or w/o AC) the gauge tends to fluctuate quite frequently.

In any event, I really appreciate any help ya'all offer. I called the mechanic that did the work and he was about as useful as a box of burnt hair.
 

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99 Seville STS, 08 STS4 N* 1SG F55
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How about the coolant temperature sensor? If it is miscalibrated it may not be kicking the fans on early enough. Otherwise I'd re[;ace the thermostat again to rule it out. If the temp spikes but comes back down that tells me that the fans are doing their job, just too late (because the temp sensor isn't turning them on soon enough) or working against a restriction (like a sticking or bad thermostat).
 

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90 Eldo -SOLD-, 98 ETC -SOLD-, 86 XR4Ti Track Car, 07 Ranger
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The 5/8th mark is one tick past center if i'm not mistaken, if that's the case then you're not overheating anything since somewhere between the middle tick and the 5/8th is 224°F where your fans kick on, they won't before that and on really hot days or in traffic it will fluctuate, especially if you aren't driving it like grandma. To get a better feel for what the actual temp is you should enable the DIC message that provides a digital readout of your water temp, the instructions are in the FSM or posted on these boards, try "enable DIC messages."

I stole this from another thread about this but look here for temp readings, they're not perfect I've noticed differences when using my DIC message, like sometimes I'll be at 185 and it will still read on the 198-220 line, also I have to be above 224 before the needle will creep to the right, and when it does it does fast relative to the gauge due to the large center range:
http://i70.photobucket.com/albums/i101/JimDphotobucket/Smallertempguagewithnumbers.jpg

I know from personal experience that in Atlanta, GA during the summer months in heavy highway and city traffic the temp will fluctuate between 210-230°F (between vertical and 1st tick past) which is fine for our engines.

I've replaced the whole coolant system on my car so I know how frustrating it can be but it sounds to me like you don't have a problem. I would say if your temps go above 230 and do not recover in under a minute then you have a problem...
 

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White Diamond '03 DHS (with DTS floor shift)
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Have you checked the belt tensioner?

The fans should be on high when the A/C is on. If the low speed relay is bad the fans won't come on at 224 degrees but will wait till high speed is requested at 229. The low speed relay might be worth checking.
 
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