Community Forums

murphylawe · 07-06-2019, 07:51 PM

Hey everyone,

I have a problem that is making me crazy and has the potential to cost me some serious $$$$.

We just bought this motorhome last month and took it on a weekend of Boon-docking. It boiled over going uphill and I allowed things to cool off, replaced the missing water and continued on to the park.

I figured it was one of the two most common boil-over causes, the thermostat or the radiator cap, so I replaced them and tested the RV on a hill. It went much further, but boiled over again.

At this point I figured it was the fan clutch, radiator, or water pump. While working from the front to the engine I discovered some moron had run a screw through the shroud in the path of the fan.

I believe I was overheating because the screw stopped the fan and burned out the fan clutch. The rig had been running on a pusher fan the whole time. This is why is would not overheat on flats and small hills.

SO... I removed the screw, replaced the water pump, had the radiator cleaned and pressure tested. I replaced the fan clutch and made sure it did not contact the fan shroud. It would turn cleanly, but with resistance from the new clutch.

I reinstalled the radiator, assembled everything else, replaced the transmission fluid, and started her up.

Sounded rough for a few seconds, but continued to run. I decided to road test, and was going DOWNHILL when the engine just died. I shifted to neutral and started it again. It ran for a second and then I just coasted to a halt.

I tried to start it again, but the ignition would only click. I checked the connections to the starter, and even whacked it with a hammer, no joy.

I removed the battery and had it tested at Oreily's, and they said it was fine. It's a NAPA battery, so I figure it has to be good. I did purchase a new starter and went back to the RV.

Installed the starter and same problem. I was finally able to get the motor to start, but it would only run at mid-rpm or higher and would die pretty quickly. I was able to get the rig into a parking lot where I will be safe. It is the holiday weekend, so I have not been able to find someone to help me out.

The motor sounds like it is struggling under load.

I ran my OBD II meter, nada...

I am pretty good with engines, have built a few, so this is making me more than a little nuts.

I am going to crank her up again and get it on video, I will attach it to this post later.

So... to break it all down; engine starts periodically, runs if you keep it in mid-range RPM, and dies when you release the gas pedal.

I have checked battery terminal, cables, and installed a new starter.

This all began after removing the center cap (front end), the air cleaner, the transmission cooler, the A/C condenser (A/C didn't work), so I just removed the cooler, and finally the radiator and fan clutch. I had the radiator cleaned, flushed, and pressure tested. I have changed the thermostat and the radiator cap.

I would appreciate your two-cents worth.

ML

Isaac-1 · 07-06-2019, 08:07 PM

You may have damaged something internally with the overheat, do a compression test on all the cylinders. Also check the condition of the ignition switch (probably green rectangular thing with wiring harness plug at the base of the steering column), they are known to overheat and cause strange issues.

MinntoMich · 07-06-2019, 08:39 PM

Murphylawe,
This is a Vortec, right? How old is or has the intake manifold gasket been changed? Still running with Dex Cool? I had a Vortec 4.3 and one day it ran fine and then one day it didn't. Week later, wouldn't even start. Changed the cap and rotor. Contacts under cap were really corroded. Problem solved.

Dunno. You got a stumper. Could a bad temp sensor give trouble to your fuel injection system?

bdpreece · 07-06-2019, 09:13 PM

Timing can cause engine overheating and also loss of power. You don't say how many miles are on the engine but you could have a worn/sloppy timing chain.

murphylawe · 07-06-2019, 10:05 PM

It is a crate engine with ~10,000 miles... ran perfectly, until it didn't.

96Bounder1st · 07-06-2019, 10:15 PM

My 96 Bounder with a 454 has a motor control module mounted above the radiator. Does yours and did you move it ? Only thing I can think of is that something may have been jostled.

Good luck, Terry

MinntoMich · 07-06-2019, 10:18 PM

Okay. Low mileage rebuild. I haven't trusted engine codes since I had a P0 code on a 07' Chrysler. Checking online gave me 5 possibilities and it ended up being the alternator which wasn't even mentioned.

I guess I would start by ticking off air, fuel and fire. If it sometimes starts and runs but struggles under load and then stalls when you let up on the accelerator that would make me want to check the fuel pressure. I'd check the throttle position, mass air flow, and manifold pressure sensors too. That's me and I'm stubborn. I know you probably don't want to just start throwing money and parts at it.

MinntoMich · 07-06-2019, 10:30 PM

EGR? You would think that it would throw a specific code and usually affects performance at idle going to part throttle. I'm under the assumption that your head and intake gaskets are okay and the coolant level is constant.

murphylawe · 07-08-2019, 08:29 PM

So here's an update folks...

Yesterday morning I got into the chair to video the engine clicking, turned the key and the GD engine started right up and ran for a bit until I turned on the leveling system and she died again and would not restart.

Soooo... since I had already checked the battery and Oreily's pronounced it 'Good', I removed the alternator and had it tested at NAPA, they said it was on the edge so I replaced it.

I also had the battery tested a second time and NAPA said it had a bad cell. It was still under warranty, so I got a new one and went back absolutely certain this was the final solution.

I have checked the wiring, all connections are snug, the battery, alternator, and starter have all been replaced.

I am going a bit nuts here and maybe even desperate. I have to be out of the park tomorrow, the rangers have been very lenient but it is time to go. If I can't figure this out, I will have to be towed and hire a mechanic.

I am a vet on a tight budget.

Any ideas would help.

tomwalt · 07-09-2019, 11:24 AM

Have you checked the ignition switch yet?
I really think this may be it. If so, you can search this site for how to replace the ignition switch.
It is located at the bottom of the steering column.

http://www.irv2.com/forums/f22/stran...ch-284988.html

MinntoMich · 07-11-2019, 12:11 PM

Quote:

Originally Posted by tomwalt

Have you checked the ignition switch yet?
I really think this may be it. If so, you can search this site for how to replace the ignition switch.
It is located at the bottom of the steering column.

http://www.irv2.com/forums/f22/stran...ch-284988.html

So... What's the connection between the Auto Level system and the ignition? Would a starter switch on the way out give this symptom?

If you already spent the dollars on a battery and alternator and this switch is a common problem have you changed it yet? Just curious and looking for your resolution if you have one yet. Hoping that you have gotten the problem licked.

tomwalt · 07-11-2019, 05:26 PM

Quote:

Originally Posted by MinntoMich

So... What's the connection between the Auto Level system and the ignition? Would a starter switch on the way out give this symptom?

If you already spent the dollars on a battery and alternator and this switch is a common problem have you changed it yet? Just curious and looking for your resolution if you have one yet. Hoping that you have gotten the problem licked.

This problem is the ignition switch that is located at the bottom of the steering column (not where you put the key in).
Some motorhome builders overload the bottom part of this switch by tapping into the accessory portion of the switch (bottom part) to run motorhome loads through it - like levelers. There are some photos in the link above 'Stranded by a faulty starter switch'.

tomwalt · 07-12-2019, 08:47 AM

There is a good picture in the 2nd post in this thread:
http://www.irv2.com/forums/f22/one-c...rt-449763.html

murphylawe · 07-19-2019, 10:48 PM

Hey Everyone,

The electrical issue was finally traced to a bad ground, but then I finally got the engine turning over and screeching metal alerted me to some serious issues.

Seems I burned up a main bearing... this engine has overheated many times I am guessing, all because some moron put a screw through the fan shroud in the path of the fan.

Had to have her towed and now have some choices to make.

1. Rebuild the current 454, depending on current bore. Will be sending it to the machine shop next week. If it comes back good... then I will be rebuilding.

2. If the 454 block is bad, he has 502 & 454 blocks ready to be built out.

I discussed possibly boring my block out and installing an RV camshaft. He told me I would also need a new computer if I changed out cams and cranks to build a stroker.

He said that isn't done as much with newer engines (this is a 1997)... said I would get better performance just building it with HD parts and adding a Banks Exhaust.

Any input would be appreciated.