Holy shit! WTF happened?!?!

[Jason C]

Bear with me here, this just happened about 15 minutes ago and I'm trying to keep my thoughts straight...

So I'm driving home from work in the beater today (1995 Mercury Villager) puttering along in my commute and as I look at the temperature guage for no reason and think "What's the use, it has never moved in its lifetime before." That was bad! Knocking on wood, I tell ya...

Before I get home I stop at the local Kragens to pick up some supplies. I had planned to do an Oil/ATF/Coolant change this saturday, so I get the necessary supplies. I also pick up some "Black Magic Engine Degreaser" to clean the stuff under the hood. I figure since I'm going to be working on it a lot, might as well make it more pleasant. It hasn't been cleaned since before BMW introduced the E36 M3. :oops:

When I get home I follow the written instructions for cleaning, as posted:

#1 Best use when engine is warm.
#2 Spray on entire engine.
#3 Let sit for 15 minutes.
#4 Use minimum amount of water necessary, spray off.
#5 Drive for 10 minutes or when engine compartment is dry.

Now, the product works as advertised, and it cut through the crap with ease. I was quite impressed! FWIW, I only used a spray bottle, not a water hose to rinse it off which made it take over half an hour. I didn't spray the water anywhere bad, like distributor/exposed wiring/intake/etc. I also checked fluid levels before I started cleaning, everything was at or above minimum. After I cleaned it off as best I could, I went for the ten minute drive. It started up right away and ran fine. All went well the first 5 minutes and then I turned it around to head back.

You can imagine the look of absolute shock and horror on my face as I glanced down at the instruments for no particular reason and noticed the temp guage all the way out of normal into the "High" range. The rest of the limp back home was spent in a flurry of expletives and astonishment.

When I got back, I immediately opened the hood and started looking, with some confusion:

-The engine felt hot, just like it did on the drive back from work.
-The coolant level was at exactly the same place it was before.
-There was nothing boiling/steaming off the engine.
-There was a very faint burnt smell, which I might have missed if I wasn't paying so much close attention. I strongly suspect that this is some overspray of the degreaser that didn't get washed off.
-Nothing was glowing red-hot, infact nothing seemed out of the ordinary.

Now I am at a loss to explain what happened. I'm not sure if I want to be driving this for more than an hour down the highway on my commute every day this week. :speechle:

[lip277]

Opinion follows as I have no first hand experience with Mercury.... But having a 1992 Explorer that is pushing 200k should get me close.... :D

Two thoughts-
1- If you were in stop and go traffic, did the electric fan come on? Maybe you got water in the relays or on something that affected the fan..... and the engine really was hot as a result... I find that doubtful, but you never know.
or
2- You got water in the wiring for the temp gage and it's found a 'new' ground or something. In that case the engine really isn't hot it just is the sensor. Try unplugging it with the engine running. Does the gage do anything? It should. I forget though if the open circuit needle position is full hot or full cold..... Oh well... Won't hurt either way to try.

Any of the other gages acting up? Was the engine 'hot' when you degreased it? IMO - You should only spray water on a cold engine. There's just too many places hot water (or rather steam after water contacts the hot parts) can get that cause problems.

I had fits for a week after washing the engine in my old 300SD. You'd think a diesel would be immune to 'electrical' issues like this. Well, I found out the engine may be innune, but the turbo controls and gizmo's going in and out of the mechanical fuel injection pump weren't. :oops:
It tool upwards of a week driving the car (as is) to finally get it to run right again. There was nothing much I could do. I cleaned (dried) each connector a couple of times that day and finally just gave up.

Oh well... It finally worked out all right. But I was sweating for a few days.....

Good luck.

[Jason C]

Ah yes, I just remembered some other details that I omitted from my original post.

Moments after I noticed the temp gauge, I turned the AC to max fanspeed and temp, because my instructor in engines said that in a slight overheat situation, it might help a bit. Strangely enough, for over 2 minutes the AC blew lukewarm air. :dunno: So I shut it off and didn't notice any difference.

I do recall the electric fans coming on at least once during my drive so I don't believe that was the problem. Additionally I was averaging 15-35mph during my little trip, I think that's sufficient to keep the airflow moving.

It does sound like something got into a connector. I'll brave a trip tomorrow to ask for advice on this. I just hope I can make it there (and back) with the vehicle in functioning condition.

Btw, it's more of a Nissan than a Ford. :twisted:

I saw the Japanese labels under the hood today! You can't fool me. ;)

[Jason C]

As it turns out, it was one of the coolant sensors. It now doesn't move from the lowest range until I've driven around for about 5 minutes (presumably when the engine has warmed up a bit). Then it goes to a little under the midway point. Ironically, I may have inadvertently made it MORE accurate. It was a good DIY lesson though.