1993 Ram3500 Van, 5.2L 8cyl EFI, 158,000 miles

Major tune: 122,500, April, 2008: Plugs, dist, rotor replaced; throttle plates cleaned, vacuum leak repaired; transmission kit, replaced 5 qts fluid.

Two problems, which may be related.

Problem one
Started about 6 months ago: In the morning, as we started driving, we'd hear the engine revving, but there was little power to the engine.

We'd crawl at 15mph for almost five minutes and then the engine stopped racing and the car drove normally. It was almost as if the engine slipped into gear.

It sometimes (but not always) helps if we warm up the engine for five minutes.

More serious problem
The Dodge loses power -- it just cuts out -- when driving at sustained 65mph, freeway speeds. It seems to be worse when going uphill.

It also happened at slower 35mph speeds, once while driving up a steep, mountain road.

In all cases, the weather has been hot.

A few times the car backfires when we lose power and I try accelerating.

I've tried removing the gas cap (vapor lock, one mechanic suggested), but it doesn't help.

Pulling off to the side of the road and turning off the engine for about 10 minutes sometimes helps.

Some thoughts:

• Could the catalytic converter be blocked cause power problems? (The catalytic converter rattles internally.)
• Is the transmission overheating? Problems with cooler unit?
• There are two electronic controls in the transmission that go bad and cause fluid pressure problems which then causes clutches to slip and burn out.
• Plugged gas filter? (It's never been changed; the fuel pump emits a high-pitched whine when we drive.

Thanks for the diagnostic help!

Steve

 

Problem one is an internal tranny issue. Problem two is a bad ignition coil.

 

I was afraid of that. The ignition coil sounds like an easy, and probably inexpensive, fix.

From your experience, does it mean rebuilding -- or replacing the -- transmission?

--Steve

 

If your cat is rattling -- CHANGE IT!

mine was, and really didn't notice it for a few months. I ended up burning out one of the valves in the head.

So, if you don't want to end up like me - with a totally rebuilt top end and rebuilt tranny, you may want to get that taken care of first. The backfiring was the first sign of the crap cat I had. Backfiring burns valves!

I've got to say that these vans are 5000+ pounds. When we are at 125K+ miles, things go wrong. I had multiple problems when I bought mine. Take care of what is wrong. I found out that you can chince with these vans when they are at high mileage.

And BTW listen to the guru -- alloro -- he's got a lot of good things to say

 

Aye, aye, sir.

Seriously, you mean take care of the ignition coil before having the trans rebuilt?

 

I would just in case the way the engine is running is affecting the tranny.

Also, when you did a fluid/filter change on the tranny, did you adjust the bands correctly?

 

The mechanic didn't note it on the invoice, so I can't be sure, but probably not.

 

It's worth asking him. Because if he did not do it, then the tranny can do a lot of slipping until it warms up.

 

Try running on some Premium for a while. I put it down to some bad gas, did not have a problem after running a tank on it.

That fix the exact problem after a crawl for 2 hour at that speed to the next gas station.

I always found that it help to do a short 5 minute run, shut down and start up again before putting on some miles.

What oil and transmission fluid are you using, is it in specs for the warmer weather?

Also a +1 for the ignition coil, it is likely warped and a new one will definitely give more power to get up hills

 

@gazza101: Somehow I don't think the transmission slippage is a fuel problem, though some people have said Arco gas, the stuff we use, isn't terrific.