I have been going through the topics as a lurker. I just bought a 1989 F250 SC Custom with the 7.3 and 5 speed for pretty cheap and started going through all the fluid changes. It ran real well on the test drive, just kind of ugly. Read up on SCA's and such which scared meinto starting with the coolant system. Got some test strips today at Napa, pH is high, SCA levels a little low, and the glycol mix shows between 50-60%. What I have a problem with is there appears to be a little oil in the coolant now, not there when test driving. The pressure cap is oily on the inside and a light coat where the overflow heads off the radiator. No coolant in the oil that I can see. The coolant in the overflow bottle is grungy looking now. The top radiator hose sucks shut as the engine cools, and I found out the new looking rad cap is 7lbs, not the 13 I think it should be. No overheating with a 20 minute trip to town and back at 70 to get to a Napa. Blown head gasket? Other ways of oil getting in there? Day 1 of ownership and already wondering if the previous owner covered up something .

 

Could also be the oil cooler on the driverside of the engine below the exhaust manifold. The oil filter srews on to it. They have been known to go bad and alow oil in the coolant. Usaully it is just the o-rings and they can be rebuilt, some times they rust out tho.

 

Thanks for the quick reply. No bubbling in the radiator with cap off and clean exhaust and oil kind of had me stumped, especially when the coolant looks good after you run it a minute. Oil in coolant did not turn up much but lots of good info searching the site for the oil cooler. Only had 2k as a budget, so you get what you can. It may be a less complicated vehicle than the VW 1.8 turbos I am used to dealing with, but still a learning curve. Here is a pic of the truck if it is allowed here:

 

We like pictures!! Decent looking truck, especially if you were at or under 2K to buy it. Oil in rad is often the oil cooler, a rebuild is fairly cheap, parts are under $50 or so, and it's a great time to flush and redo the rad etc. It can be a messy job to do yourself, but not overly difficult.

 

I am used to messes, its the wife who is not. It has 155k miles, the interior wear and other clues seem to support it. Appears to have a sat for a while before the guy I purchased from bought it. He only put 2k miles on it per year towing a boat summers only. Seals just don't like sitting and this thing has leaked all over itself for a while. A good cleaning, rebuild oil cooler, flush the radiator, and put the proper pressure cap on it appear to be on top of my to do list.

 

Nice truck ...

I agree on the oil cooler.

I figure the odds high for cover ups ... Just a sorry fact!

Thats a good thing to do, replace all fluids, then you know where they stand!
That ZF-5 5spd uses ATF, don't put gear oil in it.

I'm curious how it starts in the morning.

Might want to check the Glow Plugs and ensure they are ALL Motorcraft/Beru, if they are not, replace them ASAP.
Glow plug removal article

Also read up on the Fuel Return system and Air Intrusion.

Sooner or later Glow Plugs and Air Intrusion will become an issue!

-Enjoy
fh : )_~

 

Turns over 3-4 times, tries to start, 1-2 more turns, then starts. Kinda wondered about that, but with the current oil in coolant problem I am not driving it until fixed and looking up other problem areas to check here and elsewhere. Thanks for the tips.

 

At that point does it stay running by itself ??

Sounds more like Glow Plugs then Air Intrusion.

When messing around on top of these motors DO NOT disturb the return lines, they are the small (3/16" or 1/4") hoses that run from the Fuel filter to Injectors and Injection Pump to Injectors ... and back to the tank.

-Enjoy
fh : )_~

 

Yep, stays running with no hesitation or stumbling. On a previous note, took a look at the glow plugs and they look original. The wires going to them look untouched and the connectors look a little crumbly.

Started up quicker today, but cooler today. Maybe it just needs to be run and used regularly a bit.

 

Test your Glow Plugs, Ensure they are Motorcraft/Beru, if not replace.

*** Glow Plug Test:v2.0.1
Test light test of the glow plugs.

1. Unplug the Glow Plugs at the Glow Plugs.
2. Attach one lead of a test light to 12v+ battery.
3. Touch the other lead to the terminal on the end of the Glow Plug. (where you unplugged the harness)
   Does it light up?
   1. Yes, Chances are it's good.
   2. No, Replace with Motorcraft/Beru ZD1A for 83-86, ZD9 for 87-94.5.
4. Repeat step 3 for all Glow Plugs.
5. Reconnect Glow Plugs.

This test is susceptible to miss diagnoses and should only be used for a quick reference.
To do a positive test use a volt/ohm meter and test the ohms between the terminal and base. Should be .5 to 1 ohm resistance.

-Enjoy
fh : )_~

 

Is there a way to see if they are Motorcraft/Beru without pulling them out? I have a digital meter and can test resistance to see if they are good. I just hope the harness connectors stay in one piece, they look pretty fragile.

Decided to flush the radiator to see if it was really oil in it. Let the old stuff sit 24 hours and nothing floated up. Nothing greasy or clumpy was in it at all, just scale that sank to the bottom. Disposed of it and only the top 2" is green, the rest was old and brown with quite a bit of sediment. Test strips showed someone was putting in SCA additives, but apparently never flushed the system. Fingers crossed that it was just in serious need of a coolant flush.

 

If you want to reduce your headaches and grief, pull the GP's and replace with new. Check out wiring and fix what needs to be done. Then you'll know that system is working and you won't be tinkering with it in cold weather.

Then do the same with the fuel return system. It's simple and inexpensive (both fuel and GP's are actually). You'll eliminate a majority of your starting problems.

If you really want to splurge install an elec. fuel pump down by the tank/frame rail. It'll cost you $60 +/- and eliminate battery/starter wear when doing any work on the fuel system, like changing fuel filter, or letting the truck set idle for weeks at a time!

 

With a properly done return system, you do not need an electric lift pump, even if you let it set for months ... My 91 is totally useless in the winter, it sets all winter, starts up first attempt every time within a few revolutions.

As for telling what GP are installed ... Nope, They have to be pulled, the name/numbers are buried in the head.

And like Ditch Witch stated ... These are items your going to want to do regardless as they are the most notorious trouble makers.

As to the condition of the terminals, it's only plastic, even if it does break, the connectors are still usable, some use shrink tubing on them to hold them together or once the plastic falls off.

Motorcraft/Beru Glow Plugs go for about $10 each, you can find them for less, don't pay more.

The following is just in case ...
Injector Return Kit Installation.
You need to Install a Injector Installation Kit.

You do not need to pull the Injectors and replace the copper seals that come in the kit unless they are leaking compression around the base.

Many prefer to toss the o-rings in the kit (and I highly suggest you do) and use these Viton Return O-Rings - McMaster-Carr Item 9464K24, Viton is impervious to Diesel, has a higher heat tolerance thus remains soft and pliable longer.

For the Injector Installation Kit installation You can follow Starmilts Humorous Fuel Return Replacement Procedure, I like to cut the 6 pieces between the Injectors to 4-1/16", Use a sharp razor blade to cut the hose and Vaseline to lubricate the o-rings.

For proper fuel system bleeding you can use steps 1 through 4 and 13 through 15 of the Fuel Filter Replacement.

-Enjoy
fh : )_~

 

Wow, thanks for all the help! You just never know when joining a forum if you are going to get help or blasted for being a newb.

 

We try, We also try not to bash people, no matter what they know or don't, we all know one thing or another, we all have to learn, nobody knows everything.

Many of us are here just because we like helping others.

Some of us do have our disagreements/differences of opinions, however we all get along pretty well or at least try to.

-Enjoy
fh : )_~