HELP! Overheating, high oil pressure, No symptoms of blown head gasket
#1
HELP! Overheating, high oil pressure, No symptoms of blown head gasket
This one has stumped me, hope someone here can help! So long story, but I just installed a new radiator, and thermostat in my 78 E-250 with 351 5.8L engine. Everything went good, and car ran perfectly for a day. Then the next morning while warming it up, I notice the temp and oil pressure gauges are pegged. After driving it 5 miles it starts smoking. All fluids topped off, no leakage. Drained oil and coolant, no clouding. Checked for air bubbles in the cooling system, nothing. Changed to a 5w-30 for the colder winter temps (-28f last night!). Still nothing. One weird thing is happening too. I'll start the car randomly, and it will start cooling in idle, then suddenly the idle will jump higher, heater fans speed up, and car starts to overheat again. Do I have clogged oil galleries, or could it be electrical?
one idea I have. I'm using a magnetic oil pan heater to keep the oil in the pan warm for cold starts, could the magnet have gathered sediment to one spot, and pump sucked up a clump of it?
ANY ideas are appreciated! The local mechanics are ruthless here (since were a tourist town in Wyoming) and charged me $200 for two hours in a garage and two turns of a loose screw. Thanks.
one idea I have. I'm using a magnetic oil pan heater to keep the oil in the pan warm for cold starts, could the magnet have gathered sediment to one spot, and pump sucked up a clump of it?
ANY ideas are appreciated! The local mechanics are ruthless here (since were a tourist town in Wyoming) and charged me $200 for two hours in a garage and two turns of a loose screw. Thanks.
#2
after playing around more I've discovered it's something to do with my idle. At first start it idles right where it should, oil pressure and temp are stable, then if i give it a little throttle the idle kicks up, and back to overheating. It seems like the system is getting a jolt that it cant keep up with. Tried the same experiment in gear and nothing happened, everything stayed in operating level.
Local mechanics said they played with my timing when they had it, could this be an issue?
Local mechanics said they played with my timing when they had it, could this be an issue?
#3
#5
Reason I ask is not just any 195 thermostat will work satisfactorily in a 351M / 400. They take a special thermostat that has a "hat" on the pill end that acts to restrict the bypass more and more as the thermostat opens thus restricting the coolant flow through the bypass so that more is routed through the radiator. Using the wrong thermostat, using one for a 351W for example, if that fits even .... will result in much hot coolant contiuously going through the bypass into the water pump and back into the engine without ever seeing a radiator and a steady creeping up in temps.
So .... not saying this is your problem .... but what part number did you use?
#6
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All of our local parts guys have the wrong T-stat in their parts database. I have to ask for the correct one by part #. The one they sell fits fine, but doesn't have that bypass blockoff. Check this. The oil thing, that is just strange to me, might need a mechanical gauge to monitor actual PSI numbers and see where exactly it is going.
#7
I'm not sure if the 70s models have this but I think they do...
This sounds very much like a failing ICVR - Instrument Cluster Voltage Regulator. It's the device that reduces battery voltage to ~5V to the gauges; when all electrical gauges (except the ammeter, if equipped) wig out together in unison, this is almost always the problem.
I would expect the gas gauge to peg out, too.
A 1980-86 variant looks like so and is mounted on the back of the gauge cluster:
Factory gauges are almost useless for providing true indication of what the engine is doing, attach real gauges (aftermarket) to see what's going on.
What kind of smoke, and from where? Electrical from the dash? Oil/fluids burning off the exhaust manifold?
The idle speed stuff could be something totally unrelated, possibly the result of knocking or moving an already-crappy electrical connection someplace nearby.
This sounds very much like a failing ICVR - Instrument Cluster Voltage Regulator. It's the device that reduces battery voltage to ~5V to the gauges; when all electrical gauges (except the ammeter, if equipped) wig out together in unison, this is almost always the problem.
I would expect the gas gauge to peg out, too.
A 1980-86 variant looks like so and is mounted on the back of the gauge cluster:
Factory gauges are almost useless for providing true indication of what the engine is doing, attach real gauges (aftermarket) to see what's going on.
What kind of smoke, and from where? Electrical from the dash? Oil/fluids burning off the exhaust manifold?
The idle speed stuff could be something totally unrelated, possibly the result of knocking or moving an already-crappy electrical connection someplace nearby.
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#8
Yeah, I thought about the IVR ..... but that part about the smoke?
Maybe coincidental? I know I have guys come into my store and ask for thermostats for Ford 351s and when asked ... it's surprising how many don't know a W from a M or C, so I ask for year, model and with rare exception, nail it down that way.
But yeah, pretty sure his E250 has IVR. My 73 Mustangg once had an issue with gages, that was the IVR failing like you describe .... I thought it was 3 volts though? That was 35 years ago .... maybe it is 5 ?
Then the next morning while warming it up, I notice the temp and oil pressure gauges are pegged. After driving it 5 miles it starts smoking.
But yeah, pretty sure his E250 has IVR. My 73 Mustangg once had an issue with gages, that was the IVR failing like you describe .... I thought it was 3 volts though? That was 35 years ago .... maybe it is 5 ?
#9
Of course I threw out the boxes, so part# is history, but that would make sense. Especially since when I went back to the same shop and asked for the same part I got two different stats. So any recommendations on the correct part# to ask for? I thought it might be a stat issue in the first place, because the night the smoking occurred I noticed my bottom radiator hose was cold, and the top was piping hot, so I switched out the stat again. And come to think of it, the broken one I pulled out is a big thing, an old motorcraft part #EOTE-8575-EA. I thought it was just old, but it definitely has a "hat". And the two stats I've tried don't look at all like what I pulled out.
As far as my ICVR, I've been battling my instrument cluster and its read out since I started working on the van, but I am pretty certain the temp sending unit and new ICVR have been delivering a trustworthy temp read on the dash. As far as the oil pressure gauge though I'm not so confident.
As far as my ICVR, I've been battling my instrument cluster and its read out since I started working on the van, but I am pretty certain the temp sending unit and new ICVR have been delivering a trustworthy temp read on the dash. As far as the oil pressure gauge though I'm not so confident.
#10
And no mention of the gas gauge, either, but maybe it already didn't work.
The smoke, yeah, that could be related, but we need more details as to the kind/color/smell/location to be able to figure out much, wouldn't ya think?
I hang out mostly in 80-86 and a guy there (Gary Lewis) made an electronic version, did all sorts of micro-analysis and measuring and such, I think he figured out 5.4V was ideal.
35 years ago, yeah, your memory of such things that long ago tends to become a bit vague (ask me how I know this)....
The smoke, yeah, that could be related, but we need more details as to the kind/color/smell/location to be able to figure out much, wouldn't ya think?
35 years ago, yeah, your memory of such things that long ago tends to become a bit vague (ask me how I know this)....
#11
Look at post #12 here https://www.ford-trucks.com/forums/3...nd-tricks.html
and read thru this for more info on the 351 thermostat.
https://www.ford-trucks.com/forums/8...ermostats.html
and read thru this for more info on the 351 thermostat.
https://www.ford-trucks.com/forums/8...ermostats.html
#12
Count the number of bolts holding on a valve cover....
6 bolts = W
8 bolts = M
Radically different engines, I don't know that there's anything interchangeable between them.
Put your old thermostat back in, see if that problem goes away.
Still don't know about the smoke, though.
I would focus on one thing at a time... get the correct thermostat in there, go from there....
#13
Are you sure the t-stat is not in backwards? Not trying to sound derogatory to anyone but this can happen ive seen seasoned mechanics make this mistake. Also in my experience if the engine overheats the oil pressure drops of course i live in the south and that might make a difference. hope to hear what fixes it
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10-21-2003 03:57 PM