I just bought my wife a 2001 1500 sport 4X4 quad cab, and have a few questions. I've got several other Dodge trucks, but mostly diesels. This one has the 5.2 liter engine, with an automatic tranny. We went on about a 400 mile road trip saturday, and I noticed that it cycles a lot from torque convert locked up, to unlocked on hills. When it would do this, you could hear a noise, like maybe a vacuum leak or something. But I can't find a vacuum leak anywhere. Also, when the cruise is set, it will keep losing speed on hills, instead of kicking down on it's own. If you over-ride the cruise with the accelerator pedal, you can get it to kick down, and pick up speed again. I also noticed that we only averaged about 11.4 MPG, which I didn't think was too good really. My '96 V-10 would usually get 12 or better on the same trip.

I had a '96 1500 that was identical, except it was 2 wheel drive, and it got a lot better mileage, and had quite a bit more power it seemed like, so I think there is just something not quite right about this one, or the way it's tuned. I want to find the problem though, and straighten it out. It's really a nice truck, and we got it well worth the money.


Thanks.

 

Bandit, I just got the same truck, only with the 5.9. Good choice

I used to have one with a 5.2, and while I didn't have the vacuum sound, I'm familiar with the cycling of the torque converter. What axle ratio does it have. The 5.2 has to work some to move the heavy Dodge......while climbing hills, I'd lock out the overdrive to keep the RPMs up a little. How's the exhaust? Could the cat be plugged up?

 

check aruond the tb the air intake sometimes may work its way loose check that if that not it i am not sure i have a 5.2 and had the same problem
but with all the repairs like the AIS VALVE on the back of th tb i no longer here it

 

AIS?? IAC?

 

Ok, got an update with a little more info now. When you're going down the highway, if you come to a little hill, or go to accelerate to pass someone, the a/c will quit blowing until you let out of the gas. I take this to be a vacuum problem, but can't find a vacuum leak anywhere. I did try a little experiment, knowing that the brake booster is vacuum actuated, I pushed on the brake pedal while the a/c wasn't blowing, and as soon as I pressed the brake,the motor surged for just a second, then kind of bogged back down. As soon as it bogged back down, the brake pedal became very hard to push, like the booster wasn't working. It also seems as if the motor is laboring harder than before, and getting worse mileage.

My wife also noticed, it appears that there is a piece of black tape over the CEL in the dash.

I had dual exhaust put on, with 12" glasspacks,and echo chambers,but they just split the exhaust behind the cat. Every other vehicle I've ever put similar exhaust on, I did away with the cat also, and they were really loud. This one isn't loud at all. Has a good rumble to it, but not loud, so could the cat be bad too? I'd just do away with it (no emmission testing here), but what about the sensors on the exhaust?

I'm having some trouble figuring this thing out, but I'm not discouraged, it's really a sharp truck, she loves it, and we only gave $5,500 for it, so I'm not complaining. Just want to get it all straightned out.

 

the ac/defroster change is caused by low vacuum, either a leak or bad check valves on firewall. you cruise control is under the battery and has vac lines to it also. you need to fix this first.

after ac/defroster fixed, if cruise still acts up, replace the throttle postion sensor (TPS) on drivers side of throttle body. its about $40 at most local auto parts stores. this should help the cruise maintain speed. however, these 318 trucks are underpowered and overgeared and with larger tires, will bog down on hills whenever OD is on, unless you've regeared to compensate for large tires.

black tape over check engine light... i guess the previous owner got tired of looking at it. i've done that too. remove the tape, get the codes read by local auto parts shop, try and fix the problem. its probably important and its trying to tell you whats wrong, using its limited communication skills. these trucks are pretty nice, but they're not perfect.

edit.. pressing the brake pedal causes the OD and TC lockup to release, then when you release brake, it shifts back to TC Lock and OD, and bogs down again. if you have a tach you can see this occuring with the rpms.

 

Thanks for your suggestions. I havn't had a gas powered Ram since '98, and it was a '96 model that I never had trouble with, so this is kind of a new area for me.

On the trip where I noticed that the cruise control wouldn't maintain speed going uphill, we had the a/c on constantly, and it never messed up then. I'll have to check all the vacuum lines, fittings and such. I do own a '96 Ram 2500 V-10 thats been sitting in my shop since '99, that I'm working on getting going too (I thought we blew up the tranny, 5 spd, but it turns out it was just the transfer case), so my question here is, if I were to buy a scantool type device, will it work on both of these vehicles? And what about pulling codes on the diesels? I've got a '96 12 valve, a '99 24 valve, and an '03.

I always try to do all my own repairs and maintnace, and would really like to have the capability of diagnosing all these trucks myself. The '96 12 valve is all mechanical, so I don't have any trouble working on it, but the '99 and '03 are a different matter.

And the brake pedal thing, when I tried that, as soon as I pressed on the brake pedal, there was a momentary "power surge", but then it seemed to bog back down (I was holding steady pressure on the brake pedal), and the pedal got hard, like when a vacuum booster isn't working, or the motor is off. The RPM's didn't noticbly jump, it just seemed to have more power for an instant. I tried it several times, with the same response.

Lastly, are there any vacuum lines going to the tranny on these trucks? I assume they are completly electronic anymore, but was just wondering, as the tranny was just rebuilt right before I bought it, and I'm wondering if there could be a vacuum problem there? Or perhaps the transfer case? ( I think there are some vacuum lines that go to the transfer case to actuate the front axle?)

I know that's a lot of questions, and I appreciate all the help.

Thanks.

 

OK I have a 99 Ram 1500 4x4 with the 5.9 and have experienced the same problem with the TCC cycling but not only does it unlock then lockup while going over a slight hill, but if i hit a bump it does it. and it does the cycling when just driving down the highway on level ground. I just had my transmission totally rebuilt by MasterTech Transmissions in Wichita, Ks and it still does it. so any help would be greatly appreciated. I have had shops look at it through Real time on the road diagnostics but they couldn't find a problem..... WTF

 

hitting the brake pedal is going to disengage your TCC and Cruise control so whenever you have your foot on the gas going down the highway and you tap the break, then yes you are going to experience that slight jump in RPMs. and once you take your foot off the break, the TCC will lockup again