Having issues with my 87

[frankoman87]

My stang is running a little hotter than normal. I'm not exactly sure why because it has never done this before. It runs a little over the halfway mark on the temp gauge and before it always ran cooler then that.

A buddy of mine suggested it is because I'm running synthetic oil and that synthetic oil makes your engine run hotter. Is this true?? Should I not run synthetic on my stang???

Also my tach doesn't work for some reason. Someone suggested it could possibly be the ignition module but I've also heard it could just be a sensor that went out. Sorry for the dumb questions. Just learnin to work on it myself and any help would be appreciated.

 

[87'GTstang]

A faulty ignition module CAN cause the tach to not read, but a lot of times other things are accompanied by the symptom (there was also a recall on these things you know).

As for the cooling problems, the sythetic oil thing making your engine run like 30* hotter is a good laugh. Synthetic is so far advanced compared to conventional oil that it isn't even funny. If anything it should run cooler because there is less friction and so forth- less heat.

So when it overheats, does it do it sitting still, or moving fast down the road? The answer to this question should pretty much pinpoint the problem if accuratley answered.

 

[frankoman87]

When the engine idles, it runs at a pretty decent temperature. When I casually drive it is when it heats up to the mid point range (which I think is high)

When I'm fully throttled it heats up above the middle part of the gauge but doesn't overheat or anything.

I also noticed that sometimes my oil pressure fluctuates for no apparent reason. Sometimes when I have the vehicle throttled, the pressure seems low but still within the norm. Other times I'll be idling and the oil pressure will be low or sometimes perfect. Then there are times when I'm fully throttled and the pressure will be low or within the norm. I'm wondering if it's a sensor problem but I don't think it is because when the gauge shows the pressure at normal, the car (seems) to be running smoother which would make sense.

 

[HISSIN50]

So you are using the stock guages? Time for real gauges (water temps and oil pressure). The stockers are hardly calibrated and the IVR deadens them further.

That would be my next step.
Good luck.

 

[87TTopGT]

Hey, welcome to the board! Never heard of synthetic making a car run hotter, most likely just some function of your cooling system such as radiator aging and clogging up with gunk.
The reason the tach doesn't work is because even when they are functional stock gauges are pieces of ****! Autometer would be my suggestion to fixing the problem, I recently added tach, water, and oil gauges to mine and on the rare occasion when my stock tach works for a minute or two you wouldn't BELIEVE how far off it is! The other gauges are just glorified idiot lights, what the hell good is something with N-O-R-M-A-L spread across 90% of the face?!? Gimme a friggin break...