shane_moto33

Hey y'all....

So I am the proud owner of a 1997 Ford F-150 XLT 4.6L Triton V8 5 speed standard transmission. I have a problem however. My temp gauge, while driving will rise up to near overheating and then fall back down. Occasionally it will overheat and shut off the cylinders, but once I pull off the road, shut the truck off, I can start it right back up and she reads normal temp. It has been doing this for a while and has ran fine but after every 3 or so times I drive her, shes completely out of coolant. I've checked for oil in water and vice versa and nothing... No milkiness, or sweet smells.

Today it started to blow white smoke, but it was not overheating... just rising and falling like usual. (I had just taken my dirt bikes to the wash an may have sprayed water up in the mufflers though...) Plus the smoke would dissappear after driving it for 5 or so minustes down the road.

So what I've done to try and remedy the problem: remove and replace thermostat, drain and flush coolant/replace. Also just recently changed all 8 spark plugs.

Done some research but nobody had the same problem, the rising and falling temp gauge...Just wondering what should and could be done to take care of the problem...

Thanks much!
Shane

GraveDigger85

Initially sounded like a thermostat issue, but after reading everything it sounds like head gaskets considering your coolant level is empty and blowing white smoke. Get yourself a block tester which will test the cooling system for combustion gases entering the system while the engine is running. Easy to use and narrows your problem down to head gaskets, warped or cracked head or warped block deck should the test come out positive.

Stroked93

I have same exact year, engine and trans, mine did same thing ended up changing head gaskets

Welder7018

Mine is doing the same mine is my heads are trashed same engine and year. Mine has burt exhaust valves on 1 and 8. It stopped overheating and stopped loosing coolant once i took my thermostat out and replaced my water pump ($40 at orilleys). It stays in the normal range now and mine smokes a little when sitting at idle for a while because as stated above my heads are trashed and the valve seals leak oil causing it to burn. Is your smoke bluish or steam white? It smell like oil or sweet at the exhaust and/or does it smell like unburnt fuel? If its sweet its your headgasket if not most likely you have worn out heads causing it to burn oil and or not burn fuel completely.

Red-Ford

Sounds like we have the same truck besides the trans. I had the same problem, I got a new thermostat, didnt solve the issue, turned out to be a cracked head.

shane_moto33

Okay, so right after I posted this, I started up my truck and there was no smoke. I have driven it several times since and no smoke has come out, but I am still losing coolant, and the temp gauge still rises and falls. I was also told by a coworker that he saw a leak in my radiator... Could it just be I need a new radiator and thermostat?

iFord

I think (watch out, I'm thinking!) it could be, but I'd still be concerned about the smoke stuff. Keep us posted on ye progress.

shane_moto33

Okay today it started smoking again. Pretty sure it's the head gasket... How easy is it to replace? And I hear that Blue Devil and or Bar's Leaks works wonders for this problem. Any suggestions?

charliedyal

If you've never did a head gasket, I would not suggest this be your first one. You've got to remove everything on the top of the engine as well as everything on the front including the timing chains.

I've used the blue devil before in my step father's 4.6 scab with good results. Did it about 5 years ago and it's still running. Just be sure to follow the directions exactly.

Red-Ford

I had a cracked head, and some guy put some fluid stuff in there to fix it, I know people are going to say that was a mistake, but hey, it fixed my problem, and was only 250 bucks.