Is my bullnose going to the grave?

[86-350-460-dually]

Hey y'all. My 86 f350 7.5L is having trouble. The first sign was this morning when I went to drive her around. I warmed her up and instead of the engine temperature sensor showing the preheated truck at about midway, where she normally is, it was pegged all the way to the hot side.

My upper radiator hose was cold though. So, naturally we changed out the thermostat. The hose then gets hot, with the new thermostat, so I know it is opening up.

In days prior, we have squeeling from what we believe to be the water pump/pully when I am warming up the truck. If I get the idle over 1300 rpm's before the truck is warm, there is a loud squeel.

This afternoon, my truck was throwing out white smoke out of the exhaust. This is my biggest nightmare. I believe my oil leaks out very slowly through the oil pan gasket, and naturally my oil was low, but now milky.

I am looking at potentially changing out the water pump, but I was wondering if there was a way to test the water pump before I change it, and if there was any other thoughts, ideas or suggestions for what is going on with my truck. I still haven't gotten the trucks engine temperature down, and I'm not sure why. I don't know if the temperature sensor went bad (it's only 6 months old), or why my truck is blowing white smoke. What do I do?

[grumpin]

The squealing could be a belt. The old 1/2 inch deflection may work for some belts, but not all. I bought one of these tools to check V-Belts with. You can find them on Amazon.

http://www.daycoproducts.com/dayco%C2%AE-belt-tension-gauges

My temperature gauge goes high in the normal area, as in at the "L" but just under the line. Then I'll look down and it will be halfway. But, every time I've checked it with a temp. gun it's at or around 195♀. I'm considering an aftermarket gauge.

If, big if, there is coolant in your oil and your engine is in good enough shape, the head gaskets should be replaced.

[ArdWrknTrk]

If, big if, there is coolant in your oil and your engine is in good enough shape, the head gaskets should be replaced.

I would always do a leakdown test before condemning the head gaskets.

Gary is a big proponent of this as well.

There are other possibilities that are better (corroded water pump backing plate) or worse (cracked head)

At least you would know what's wrong and where the problem is before opening the engine up.

Water is not a good lubricant and naturally it will sit in the bottom of the pan where the pickup is.

It's also good to check accessories while you have the belts off.

Try turning the power steering, water pump and alternator by hand.

Do any of them feel rough or have any radial play?

How about the fan clutch? Does it turn smoothly when cold? Not free, but smooth.

Any one of these can squeal with the engine running.

 

[Gary Lewis]

If, big if, there is coolant in your oil and your engine is in good enough shape, the head gaskets should be replaced.

I would always do a leakdown test before condemning the head gaskets.

Gary is a big proponent of this as well.

There are other possibilities that are better (corroded water pump backing plate) or worse (cracked head)

At least you would know what's wrong and where the problem is before opening the engine up.

Water is not a good lubricant and naturally it will sit in the bottom of the pan where the pickup is.

It's also good to check accessories while you have the belts off.

Try turning the power steering, water pump and alternator by hand.

Do any of them feel rough or have any radial play?

How about the fan clutch? Does it turn smoothly when cold? Not free, but smooth.

Any one of these can squeal with the engine running.

I agree with the others - do more testing before pulling the heads.

But I'm not sure I understand all you've said. The temp gauge still pegs? How quickly after starting? When do you get the white smoke? And are you losing coolant?

[85lebaront2]

I agree with the others - do more testing before pulling the heads.

But I'm not sure I understand all you've said. The temp gauge still pegs? How quickly after starting? When do you get the white smoke? And are you losing coolant?

Belt squeal on these can be the alternator belt, it can be a real pain to get tight enough. I agree with checking for problems in the various belt driven items, if it is anything like mine used to be there is a real rat's nest of belts on the front of the engine, any one or two (water pump/power steering pump) can squeal on a cold start.

White smoke can come from a number of places, automatic transmission modulator bed (not likely since yous is a manual), brake booster (leaking master cylinder), coolant leak at the manifold front or rear into the adjacent intake port (1,4,5,8). Head gasket leaks are not common on these as Ford's gaskets are composition unlike some others who use stamped steel, head cracks are also not common on these either.

Cylinder leakdown testing is one of the best ways to find issues with rings, head gaskets or valves. FWIW, a bad head gasket will almost always push coolant out of the radiator as the leakage has to go somewhere and with a closed thermostat it pushes coolant out of the heads and intake resulting in a huge air bubble in the upper part of the engine.

[86-350-460-dually]

Belt squeal on these can be the alternator belt, it can be a real pain to get tight enough. I agree with checking for problems in the various belt driven items, if it is anything like mine used to be there is a real rat's nest of belts on the front of the engine, any one or two (water pump/power steering pump) can squeal on a cold start.

White smoke can come from a number of places, automatic transmission modulator bed (not likely since yous is a manual), brake booster (leaking master cylinder), coolant leak at the manifold front or rear into the adjacent intake port (1,4,5,8). Head gasket leaks are not common on these as Ford's gaskets are composition unlike some others who use stamped steel, head cracks are also not common on these either.

Cylinder leakdown testing is one of the best ways to find issues with rings, head gaskets or valves. FWIW, a bad head gasket will almost always push coolant out of the radiator as the leakage has to go somewhere and with a closed thermostat it pushes coolant out of the heads and intake resulting in a huge air bubble in the upper part of the engine.

How do I go about doing a cylinder leakdown test? I'd love to do that.

Gary, the truck is still running really warm. On the "normal" letters, we are sitting right about at the L. I did haul a 16k lb RV with it last night with the engine temp that high, and the RV's disc brakes unreleased. It was a beast to pull 10 miles but my engine temp didn't get any hotter than sitting on the L.

I do believe I have coolant and oil leaks. How fast does it take to get that hot? I'd say it's about as fast as the truck normally takes to get up to engine operating temp.... Maybe 7-10 minutes? Normally my engine temp gauge will just stop right about halfway and point exactly at the midway mark. The day prior, it was doing exactly that and then I woke up and I couldn't keep the engine temp down.

Where can I check the engine temp manually? I have a heat gun sensor dew-hickey.

[Gary Lewis]

How do I go about doing a cylinder leakdown test? I'd love to do that.

Gary, the truck is still running really warm. On the "normal" letters, we are sitting right about at the L. I did haul a 16k lb RV with it last night with the engine temp that high, and the RV's disc brakes unreleased. It was a beast to pull 10 miles but my engine temp didn't get any hotter than sitting on the L.

I do believe I have coolant and oil leaks. How fast does it take to get that hot? I'd say it's about as fast as the truck normally takes to get up to engine operating temp.... Maybe 7-10 minutes? Normally my engine temp gauge will just stop right about halfway and point exactly at the midway mark. The day prior, it was doing exactly that and then I woke up and I couldn't keep the engine temp down.

Where can I check the engine temp manually? I have a heat gun sensor dew-hickey.

All sorts of questions to ask/answer. First, do your fuel gauge and oil pressure gauge appear to be reading normally? I ask because they and the temp gauge are run by the Instrument Cluster Voltage Regulator, which is a real silly little circuit. If it goes bonkers, and they do, then all three gauges go wonky - together.

As for measuring the temp manually, do that on the side of the thermostat housing, or the upper radiator hose after the thermostat opens.

And this page from Mobil does a good job of describing a leak-down test.

As for what tool to buy, I made my own so don't have experience with any one tool. However, whatever tool you get should have two gauges, one before and one after the orifice. And, it should have several spark plug adapters so it'll fit several engines. Plus, a pressure regulator as part of the kit is particularly helpful as you frequently have to adjust the pressure for each cylinder because of more or less leakage that changes in the high-side pressure due to flow.

My procedure is to bring the cylinder up on TDC, screw the plug adapter in, adjust the regulator to 100 psi so that you have a constant reference, and then read the low-side gauge. An 80 psi reading means you have 20% leakage, which is bad. So now you go listen to the intake and exhaust to check for valve leaks and dip stick tube for ring leakage, and then check the radiator for head gasket leakage or cracked heads. Oh - also put a hose in the spark plug hole of adjacent cylinders and put the other end to your ear. Head gasket leaks can frequently go into the adjacent cylinder.

[86-350-460-dually]

All sorts of questions to ask/answer. First, do your fuel gauge and oil pressure gauge appear to be reading normally? I ask because they and the temp gauge are run by the Instrument Cluster Voltage Regulator, which is a real silly little circuit. If it goes bonkers, and they do, then all three gauges go wonky - together.

As for measuring the temp manually, do that on the side of the thermostat housing, or the upper radiator hose after the thermostat opens.

And this page from Mobil does a good job of describing a leak-down test.

As for what tool to buy, I made my own so don't have experience with any one tool. However, whatever tool you get should have two gauges, one before and one after the orifice. And, it should have several spark plug adapters so it'll fit several engines. Plus, a pressure regulator as part of the kit is particularly helpful as you frequently have to adjust the pressure for each cylinder because of more or less leakage that changes in the high-side pressure due to flow.

My procedure is to bring the cylinder up on TDC, screw the plug adapter in, adjust the regulator to 100 psi so that you have a constant reference, and then read the low-side gauge. An 80 psi reading means you have 20% leakage, which is bad. So now you go listen to the intake and exhaust to check for valve leaks and dip stick tube for ring leakage, and then check the radiator for head gasket leakage or cracked heads. Oh - also put a hose in the spark plug hole of adjacent cylinders and put the other end to your ear. Head gasket leaks can frequently go into the adjacent cylinder.

Thank you for that Gary.

You actually make a good point about the dash clusters. In fact, my oil pressure doesn't read. The night prior and since, my fuel gauge has been reading correctly but it has been doing something weird. If empty to fuel is like 10-2 on a clock. Mine now shifted to 12-3ish. And obviously my engine temp gauge is off too.

[Gary Lewis]

Thank you for that Gary.

You actually make a good point about the dash clusters. In fact, my oil pressure doesn't read. The night prior and since, my fuel gauge has been reading correctly but it has been doing something weird. If empty to fuel is like 10-2 on a clock. Mine now shifted to 12-3ish. And obviously my engine temp gauge is off too.

You can make a much better replacement, as described here: Electrical/ICVR.

[Gary Lewis]

Thank you for that Gary.

You actually make a good point about the dash clusters. In fact, my oil pressure doesn't read. The night prior and since, my fuel gauge has been reading correctly but it has been doing something weird. If empty to fuel is like 10-2 on a clock. Mine now shifted to 12-3ish. And obviously my engine temp gauge is off too.

I should have also said that I believe you've found the problem. Your fuel gauge is reading much higher than it should and your temp gauge is reading much higher than it should. They are run by a common culprit that is known to cause that problem.