Engine temperature variation

[Biloxi Red 96]

I'm making my very first post, after much lurking and reading. I've not seen anything regarding engine temperature fluctuations, so I figured why not ask for help. I'm not really sure how to ask this, so I'll just describe the problem(?) and go from there. As everyone knows, the engine temperature gauge has an arc in which NORMAL is spelled out. Usually the needle indicator points to midway between the A and the L. At least it does on mine. Anyway, as the outside air temperature goes up, and if the engine is pushed a little harder than just normal stop and go traffic, the temp indicator pushes up to a range from the A/L position to the O/R position. Is this actually "normal"? I started to notice this after changing the oil and filter, but to be honest, it may have done it before the change, since I didn't drive it long after buying the car before changing the oil. I used Havoline 5W30 and the Motocraft filter. On a 700 mile trip, the temp did go up at cruising speed, but it was never in danger of overheating. Now the really unusual part (at least to me) is that while driving down a mountain road, I put the transmission in 2nd to use the engine as a brake (since the brakes are so wonderful, but that's another story), and while that worked extremely well, a side effect amazes me and I have no answer for it. While using the engine as a brake, I could see the temperature indicator actually dropping back to between the A/L position and then a little lower. Is something wrong with any of these pictures, or what? Anyone have any comments, suggestions or anything? I thought I knew a little bit about cars, but I'm at a loss here. Also, should I change oil again, and if so, what should I use that will help lower the engine temperature? Thanks in advance for any help! Sorry for such a long post.

Lee

 

[magic_marker]

RE: Engine temperature variation

Welcome, welcome! Glad to see a new poster!

Based on my experiences, I think your temp gauge is acting just as Ford engineers designed it.

Engine braking has the same effects on mine.

For a real treat, turn your HVAC panel to "Off", and watch your temp gauge gradually climb up to the "R". Then put it to "Auto" (at a temp that will engage the AC) and watch the gauge *drop* back to the "A/L" range.

Very unusual.

 

[joeychgo]

RE: Engine temperature variation

My guage never fluctuates....... except a tiny bit. It might be on the topside of "A" or the topside of "L" never more of a fluctuation then that, regardless of ac or heat being on or off

 

[dsinclair]

RE: Engine temperature variation

Lee -- welcome aboard - glad you're here.

As the rest of the gang stated - I wouldn't worry too much about a bit of sweep in the gauge. The engine is just "breathing" as the thermostat opens and closes - based on internal temperature.

If you smell anti-freeze - or the computer sends out an alert - THEN you need to worry.

It probably wouldn't hurt to have the system flushed and new coolant put in - just so you're sure. The only other thing that could cause wide swings in engine temp is a sticky thermostat - but you would see a sharp rise - then a sharp fall in temp - as the thermostat finally opened. My thermostat actually broke in two pieces on my '98 - at 40,000 miles - and THAT caused some interesting readings for sure.

 

[jhaas_lsc]

RE: Engine temperature variation

For a real treat, turn your HVAC panel to "Off", and watch your temp gauge gradually climb up to the "R". Then put it to "Auto" (at a temp that will engage the AC) and watch the gauge *drop* back to the "A/L" range.

Very unusual.

No kidding! I thought I was the only one.

 

[Biloxi Red 96]

RE: Engine temperature variation

Thanks everyone for sharing experiences. It's apparent that not all engine temperatures behave the same way. I've had GM most of my adult life, and none of those cars did this, so the fluctuation in temps with a Lincoln is new to me. My dad has a Crown Vic and the temp rarely varies, so you can see why I am a bit concerned. Everything else with the Mark seems to be just fine, and I'm basically of the "if it ain't broke, don't tinker with it" school. I do basic fluids and normal preventive maintenance, and that seems to serve me well. One question I still have though, is does the type of engine oil make a difference in all of this, and if so, what should I change to? Thanks again to everyone for any help.

Lee

 

[budpytko]

RE: Engine temperature variation

Lee,
I think most of us use Mobil 1 Synthetic 5W-30 or an equiv. If it's good enough for jet engines with all THAT heat, it's good enough for me! You say you've been lurking for a while, so you MUST have seen notes from other members to check the Main Page and you will find a number of helpful articles about how to take care of your Mark. If after checking them out and you still have questions, ask away! I'm sure you may even come up with some NEW ones even the founders can't answer.

 

[driller]

RE: Engine temperature variation

For a real treat, turn your HVAC panel to "Off", and watch your temp gauge gradually climb up to the "R". Then put it to "Auto" (at a temp that will engage the AC) and watch the gauge *drop* back to the "A/L" range.

Very unusual.

No kidding! I thought I was the only one.

With the AC on the cooling fan switches to high for proper condenser operation, and subsequently it could *drop* the engine operating temperature.

 

[dirty old man]

RE: Engine temperature variation

First of all, I'll disclose that I have a vested interest, I'm an independent Amsoil dealer { see my ad in advertiser's forum}.

But I also have a great deal of experience in engine oil related topics, after all I tore down my first automobile engine {a 34 Ford flathead} 49 years ago, and this was after quite a few Whizzer Motor Bikes, Cushman Motor Scooters, and Briggs and Stratton & Clinton lawn mowers.

Since then I have been involved in or built engines for everything from 13,000 rpm modified Briggs & Stratton open class WKA dirt track go karts, to big inch engines for Truck Pulls, to stock grocery getters, to oval track racing engines.

I also have maintained a close friendship with numerous mechanics and automotive machinists all these years. All agree that there are 2 important points to consider in motor oil choice.

One is that the oil must have an adequate film strength at high temps to give protection to bearings, etc.

The other is that the oil must reach the critical areas in bearings, etc, as soon as possible after startup.

There was a time when you had to give up a great deal on initial oiling in order to maintain adequate viscosity after the engine heated up and was put under heavy load and high rpm. You had to just hope that thje heavy oil got to the bearings before that cold startup did too much damage.

Now, however, with the advent of synthetic oils, it is possible to have the best of both worlds. A good synthetic {especially Amsoil} has the light viscosity needed on cold startup yet maintains necessary film strength under high temps and rpm.

A good friend who owns and operates an automotive machine shop, and who is an absolute Ford nut with a collection of restored Edsels including on customized 58 with chopped top and Cobra DOHC 32v engine, has 2 comments specific to our engines.

One is that the weakest structural point is the connecting rods {sintered metal}. The other is that our engine has the longest path from the oil pump to the cam journals of any US engine. The aluminum head material serves as the cam journal bearing, and can mean loss of a head unles you find a shop sharp enough to bore and rebush.

His solution for the first problem is Eagle H-beam billet rods, and for the 2nd, synthetic oil, which can be thin enough to get there in a hurry and still hold film stength hot.

I am running Amsoil 0w-30 in my MK8, and Amsoil filter. I change the filter every 6 mos. or 12,500 mi., and the oil every year or 35,000 miles.
.

 

[Nysbadmk8]

RE: Engine temperature variation

i trust NO OIL for 35,000 miles, no matter how good it is oil still collects unburnt fuel, depoisits, water/antifreeze and No matter how good it is it breaks down slowly. 3,000 or less and dont vary from that!

 

[Ponyfreak]

RE: Engine temperature variation

I diassagree that the rods are the #1 problem. They are #2. The #1 problem are the pistons. Of course if you are stock you will nto have a problem with either one of them.

 

[ROCKYTOP]

RE: Engine temperature variation

I agree with Peter! 3,000 miles maximum is best. You don't have to be a rocket scientist to look at the dipstick after you have just changed your oil (no matter what brand or be it synthetic or not) and then again after 3,000 miles look at it again and see a noticable difference in it. It gets beat to death flying around in your crankcase and everywhere else it has to go! Also, IMOP, most modern oils leave enough lubricating film to protect your bearings, etc.. on a cold start-up, unless you're one of the types that has to continuously rev up the engine before the oil has a chance to be pumped throughout your engine.