Engine or Transmission?

[Smartstream]

One thing many overlook is these coaches weigh nearly three times the cars and trucks we are used to driving, they are slow on the hills... The Isuzu is even slower, but it will get you there. Back off the throttle a bit, sit back and enjoy the ride.

[4airsteam]

Thank you for your advise,

how are your rear leaf springs my are pretty loud with popping and squeaking. Any remedies for that?

I was looking into installing a headers have you heard of anybody doing that to 454?

Best Regards

Peter

[Waipio Rim]

Only the front of your rear leaf springs is attached to the coach. The rear part of the springs has been cut off and is supported by air bags. You need to make sure that the bags are holding air and supporting the coach. If they are flat the coach will not be safe to drive and you will get noise.

The stock cast iron manifolds are known to develop problems, headers are an improvement. Both of my coaches have them, and I will be replacing one set with new Doug Thorley headers soon. If you get them, make sure that the fuel line passing near them on the right side of the coach is far enough away and/or protected from heat.

[Keyair]

To the engine overheating question...

Here is my $0.02 based on what I know, and have experienced personally:

1/ The stock cast iron exhaust manifolds are known to be restrictive, hold and radiate heat. Then they warp.

2/ When they warp, it blows the gaskets, and/or pulls the header bolts out or breaks them. The localized superheating warps the manifold worse.

3/ The hot exhaust gases then blowtorch the plug wires, but even without blowing gaskets, the wires are vulnerable to heat damage.

A few things to think about:

1/ Exhaust Manifold, will need to be checked for flange warp, and machined if needed(99% certainty). Bolts need to be replaced and high quality/correct length. High quality gaskets, I heard solid copper gaskets are best. Retorque after a few heat cycles.

2/ Airstream side shields between chassis and body MUST be in place. See notes about cooling and exhaust manifold warpage in the GM P30 Chassis Manual. Without them, the manifolds loose cooling air flowing over them.

3/ Plug wire protective metal shields were installed originally for a reason! High quality, high heat silicon plug wires are mandatory.

4/ I think the '87 had twin smog pumps. Make sure they are present and correct, and working properly... they inject cold air into the exhaust manifold, which cools it. Had a friend who removed his, and he had multiple header warpage issues.

Moving forward....

High quality tubular headers/exhaust are well known to aid power/torque on the 454, and ceramic coating is the best thing you can do. Banks Power kit is expensive, but the best.

Make sure your upper radiator shroud is in place?
Good correct, AC Delco Viscous fan clutch?
Is your ignition timing correct?
Is you engine running too lean?

If the 454 engine has an issue and is ready to be replaced, it makes sense to weigh a Cummins swap, but not before, unless you have money to burn.

[GinaParmesan]

Originally Posted by 4airsteam

Ok, will do. I am also thinking to replace it with two headers. What do you think? I don't have a CAT converter as it goes straight into the pipe but I haven't heard anything regarding is this engine powerful enough to tow a car and drive comfortable 2500rpm at 65mph?
Thanks

I’m towing a 3,500 lb Chevy Volt with no problems. Usually sticking to 60 mph on flat terrain and slowing to about 20-25 uphill.

The two engine problems I had were 1) fan clutch failed and 2) heater hose burst. With 1) engine was super loud and sounded like it was stuck in first gear. Power and speed were both affected, and I can’t remember for sure but I think RPM’s were normal. Maybe check that?

[TinPeddler]

Owned a 87 Pinnacle 33' very similar coach, added Banks headers, gear venders aux trans. Made a big difference in power and mileage (not that it's any good). Being a carberated non cat chassis you need a good tune to keep it running right. Don't know how many miles on yours but you might want to check when it's if the radiator is evenly hot if not you'll need to recore. You might want to add additional electric cooling fans up front. You can get a lot of miles off that chassis, good luck.

[windfallsp]

Peter,

Although we now have an A/S diesel pusher, we had an '85 Classic 345 for several years. We bought it when the odometer was around 66K miles and put another 60 on it.

The performance shop advice you've gotten is good; we used one and the advantage was that they not only understood carbureted Chevy engines, but they could fabricate parts for which no replacements could be found.

Here's what we did to get our 454 running cool and purring: installed transmission cooler, thermostatically-controlled superfan, Banks system + all-new exhaust, and new radiator core.

All that said, you really need to calculate your rig's towing capacity and then compare it to what you're asking the 454 to do. (Don't forget to include the weight of your dolly in your calculations.)

Even with all the mods we made, and towing our relatively light-weight 2007 Subaru Forester 4-wheels down, our 345 still slowed appreciably in the mountains. You may need to sell the dolly and switch to a lighter-weight, flat-towable passenger vehicle. You may also need to reconsider if you really need all the gear you're packing into the coach and toad, and may want to avoid traveling with full tanks: all that stuff just makes the engine work harder.

Happy trails!

[1969fowler]

When we got our 1992 350LE in 2010, we added a Banks system. This year we developed a backfire and seem to have cured it with a new distributor, spark plugs and wires. We are currently on our second trip since the last replacements and are hoping we have cured the backfire on long pulls up hills permanently.
Good luck

[1969fowler]

to add to my post, we tow a 2012 Ford Escape 4 wheel drive and all wheels down.

[Kota]

If I were in your shoes I’d look at the 454 drivetrain of a 96 classic 360. They are on a p30 chassis. I drove one for a guy and was impressed with the performance. Find that combination in a donor vehicle and do a swap. Ideally from a vehicle of similar weight.

[Toddnazus]

I understand your situation completely..... We have a 1985 345, with the 454 chevy.... We blew out gaskets and overheated a lot.... WITHOUT towing....

Our resolution was multi-fold:
1) Switched from 3 speed to 4L80E 4 speed transmission (MUCH quieter too), we run at 2200 rpms at about 65mph now.
2) Aluminium radiator
3) Oil cooler

We haven't had issues with overheating... but now I'm starting to wonder if we can tow.... or if we should leave well enough alone...

[davejay]

Hey,
I had a 345, and towed my 8500 pound deisal excursion to North Dakota. I was not being nice to it on the hills. Had no trouble pulling that weight.
I'd say first off, check your fuel pump. Does it has an aux pump in the rear. Is it working. It'll be buzzing when your running the motor. Next timing. Make sure your timing is correct. May need a tune up. Fuel. How old is your fuel. Throw some octane boast in the tank may fix it. Our fuel is lousy no power . Check your fuel filters the one on the frame too buy the battery box. Carb, is your four barrel opening when you put your foot in it sometimes they stick close. Been there , dumb question.... Do you have your E Brake on?
Clogged exhaust? Rare. If your trans is acting up. It'll be slipping most likely, and getting hot. When this happened, did the trans blow fluid out the back seal? You would have smelled it, it's pretty obvious. Were you pulling a hill? Did it kick down to 2 nod gear? Could be a valve body clogged up. I don't think you got an engine or trans problem.
My guess. Bad fuel, aux fuel pump, carb stuck, Maybe timing, check your brakes. Tag axle brakes sticking? Bad coil possible. DJ

[davejay]

Hey,
One more thing. Check this first. Thermostat. If it's opening, but not all the way, she'll run perfectly fine, until you need power, or push it a little. Then, it ll start overheating, then, loose power, then, start overheating manifolds, then, missing stumbling, and overheating the radiator. That's what I'd check first. Did you loose or is the fan belt loose? DJ

[Toddnazus]

Note: We didn't have as high of temps, but still temp issues. We've added a transmission cooler, and.... had the 4L80e transmission programmed properly.... now we have GREAT temps in BOTH the radiator and engine. The transmission running hot was 'super-heating' the radiator, and not allowing the engine to cool properly.

[davejay]

Hey,
That makes perfect sense. That's my problem with the trans being cooled by the radiator. Under normal conditions, it does what it's supposed to do. But I think we are on the upper end in terms of capabilities, when it comes to towing and cooling. I routed my super heavy duty trans cooler to bypass the radiator. I'm not to concerned with the trans running to cool. Well, I'm glad you found the problem. Looks like all got it wrong ,eh? Take care. DJ

[Paul J Mauro]

have not heard from anyone who pulled out the original 454 and popped a new one in
that smy plan but our local shop needs some advice
does the engine come out the nose after you remove the heads ? or do you try to strip off manifolds and all in the doghouse first ? thanks for the help

[Paul J Mauro]

anyone taken out the original 454 and put in a new crate engine
need some advice on the process
thanks

[chiefair]

You can read about my swap here: http://www.airforums.com/forums/f311...-a-140290.html

I took mine out with the heads on it. I removed the carb, exhaust manifolds - and should have removed the distributor. You need an engine lift plate that bolts to the intake manifold in place of the carb. I had to bolt the arm of my engine hoist directly to lift plate with no chain to get enough clearance. It is a tight fit, but it will come out. I had to jack up the front of the motorhome a little to get the angle right for the motor to come out.

[stream3]

Originally Posted by Paul J Mauro

anyone taken out the original 454 and put in a new crate engine
need some advice on the process
thanks

My'88 345LE that really looks like an 89 (still not sure why except I'm guessing it was titled late 88 but the factory had switched over to new style), goes in next week for a new 502 HT and overdrive transmission, Banks, etc. I've owned two 88/89 345s with stock 454's and I'm ready for fuel injection and a lot more horsepower/torque and reliability. I've had issues with the old lump in there now, and it has almost 200k on it. Of course it's running well at the moment, though, but I'm really looking forward to this. If all goes according to plan (uh-huh), I'll have it back by late January. He's taking it out the front as I believe that's the only option. The shop I use has done this multiple times, but it's a big job nonetheless.

[ROBERTSUNRUS]

Hi, 220 degrees is not overheating. If your radiator is puking, then you might need to have a block test done. Also a lean carburetor or incorrect ignition timing can be the cause of exhaust manifold glowing, warping, and blowing gaskets. And this will cause plug wires to melt too. A proper major tune up might be all that you need.