WuTang

1993, Ford F-150 5.0, 184K on the odometer.

Engine is missing, enough to shake the truck, does alright on higher speeds. Exhaust smells funny (this may be due to some injector cleaner in that tank not long ago?), can't really describe it. Not seeing any prominent smoke of any kind coming from the exhaust. Changed plugs and wires, cap and rotor, all Motorcraft. #5 and #6 plugs came out white, the rest were fine. Radiator has some kind of awful looking stop-leak in it from the PO (will post picture below). The reservoir runs dry in less than a day with minimal driving (two ways, 8 miles at highway speeds, 16 miles total). No signs of leaking. Oil isn't milky or abnormal, I separated some into a water bottle and let it sit for about a week, didn't separate like oil and water.
Not overheating at all.

The only thing I can think of is a blown head gasket, but it's not making sense to me.
If this is, indeed, a blown headgasket, do the heads HAVE to be machined after replacing the gasket or is not doing it asking for trouble later on and is very critical?
My concern is this is my daily driver and this is being checked and possibly done this weekend, when machine shops won't be open. Next opportunity I would have to work on it would be the following weekend.

Radiator after removing the cap:
https://sphotos-a.xx.fbcdn.net/hphot...19553553_n.jpg

broncojunkie

You sure that's not oil in the radiator? Regardless, I think it needs flushed out. If it is stop leak, then it would probably cover up any leaks you may have, making it hard to figure out what's going on. If coolant is disappearing and you don't see leaks, then I'm leaning toward head gasket. The fact that you smell something strange from the exhaust kinda supports this. It may not be bad enough to see white smoke, but still enough to smell it.

I'm just guessing and I'm by no means an expert, but that's what I'm thinking. And if you're going through the trouble of removing the heads on a motor with 180,000 miles, then I would just do a valve job (presuming cylinders, crank, bearings, etc seem to be ok. You should be able to check for warping with a straight edge and deeper feeler gauges, I think, though. Been quite a few years since I've done that stuff.

WuTang

Doesn't appear to be. Seems like mud to be honest. Stuck my finger in there and scooped it out, seemed just like mud, really strange stuff.
Should I try starting the vehicle with the radiator cap off and see if it splashes and is pushing out exhaust?

Unfortunately I'm short on cash to be able to do much more. Would the cost difference be all that much?

fordka

Im pretty sure your radiator needs a good coolant change and flushing out like mine. My coolant is a thick chocalate brown color so mine and im sure yours needs a good cleaning for starters

broncojunkie

I would say that is stop leak...maybe the "bar none" stuff (Prestone makes a similar one). It works good in a pinch, and I've used it in the past for a good 6 months or so. Problem is, it can clog up the system...usually the heater core. Are your hoses in good shape? I would get me a Prestone "Flush-n-Fill" kit ($6-8). Install it and flush the system really good. If it's the head or head gasket, you might see some white smoke from the exhaust...or, hopefully, a good ol-fashioned radiator leak (that would be a good thing, since it is much better than a head gasket). Just fill with water until you're finished checking things out. You can easily add coolant later, using the Prestone kit (don't leave water in there longer than a day or 2).

This is just the first and easiest step to figuring out the problem...especially since it looks like the system needs flushed, anyway. If it does look like something major, I guess you could just add coolant and some more stop leak. Definitely not the best route, but worse case scenario is you blow it up and have to find a decent used motor. Just being practical here, but you get the idea. Flush it and go from there.

broncojunkie

Oh, and my first post should have said "feeler gauges" ...not "deeper feeler gauges". I'm not crazy about this Kindle Fire HD.

Aktech

https://www.f150forum.com/f10/how-re...es-obdi-10907/
Pull codes,sounds like your running lean on #5 & #6. This (could) be the cause of your head gasket going out (if it is out)because it is running hotter on 5 & 6. I bet you get a lean running hego code. Is the exhaust look white?

WuTang

Okay, just an update, sorry guys, have been busy with work

Realized I'm not losing coolant, it just leaks out somewhere from the reservoir. The radiator coolant levels don't change at all, so we decided to not do the head gasket. I was a dummy and gave the wrong cylinders, it's #1 and #2, the front two on the passenger side.
Replaced the fuel filter last night and it seems to be running a little better, but still not 100%. It still is somewhat slow on acceleration and idles a little rough. When I changed the spark plugs and wires I managed to shatter a couple vacuum lines, so I'm going to fix those and check codes. Any other suggestions on stuff I can try?

1994 F-150 Driver

There are two pretty simple ways to see if your head gasket is blown, and one a little more complicated.

First test:
Check your engine oil color. If your head gasket is blown your oil and coolant will almost always mix leaving the oil a tan/cream color. Almost like coffee with too much cream. If your oil is tan your head gasket is absolutely bad. If it's not tan, it's a good indication but not an absolute, that your gasket is good.

Second:
Take the radiator cap off and have a friend crank the engine while you watch from a safe distance. If your head gasket is blown exhaust gasses would force coolant out of the open radiator and spew. If it does spew your head gasket is absolutely bad. Like the first test if it doesn't spew it is a good indication, but not and absolute.

Third:
Perform an engine compression test. This is the most effective way to positively test your head gasket, but it does take a little mechanical know-how, time, and correct tools.

The first test is a good start because it is easy. Also, about 90% of blown head gaskets will cause oil and coolant to mix in the oil pan. The second test is another easy test to do if the first is inconclusive. It also is a secondary test to ease your mind if your first test is negative, but you still have suspicions. The third test is an absolute, but it's not completely necessary unless your other two tests point to a bad gasket or are inconclusive.

Hope this helps.

WuTang

I've done the first two and both are negative. Should I bother doing the compression test?