My 1995 Caravan Shakes under load HELP

[joe wilkerson]

I have a 1995 dodge caravan(sport LB) with a 3.0 and automatic overdrive. I parked it a year ago and am just getting back to making it happy again.

The problem is that it shakes like the front wheels are going to fall off(that's what it feels like) when I apply power or go up hill and put the car under load. If I back off the gas it smooths out just like glass, if I feed in some gas , it starts shaking violently( yes violently)

I have changed the axels, and all the motor mounts. I put on different tires in the front nothing helps. I had it down to an alignment shop and told them to look it over to see if anything they could see would cause the issue.

The car has always driven like a dream untill a year ago as I was on my way to Phoenix from Ca, I was going up a grade and it just started to shake till I backed off and has had the problem ever since. I had to nurse it all the way to Phoenix, just easing in on the gas till I got to 70-75 on the flat and it would run fine, but as soon as I hit a hill I was back to 30mph til I got on the flat again. I'm going to put it back on the road if I can get the shakes fixed.

I have read on line where multiple folks have had the same problem with their caravan.... but no good answers, I need someone that has had the problem and cured it,

thanks for the help

Joe
Riverside, Ca

[Vistal]

Id look into new plugs wires and fuel filter 1st. since it was sitting a long time they may be gummed up even worse. Then look into fuel pressure and fuel injectors. if nothing i take it in and have them look at MAF / TPS sensors.

[TomQuick]

I agree that I would look to the engine. You've already gone over the front end, and you say that it drives smoothly, even at 70, as long as you aren't giving it a lot of throttle, so I would guess that the shaking you are feeling might be a serious misfire. Give it a good tuneup, air filter, fuel filter, plugs, wires, and have someone go over the fuel injection to check proper pressure, and be certain that the injectors aren't gummed up.

[joe wilkerson]

I completed the tune up today and NO CHANGE, new plugs, new wires, new cap and rotor. What I have replaced is the two engine mounts, the transmission mount, both axels and a complete tune up. The front end was looked at by a frame shop and aligned. It has two brand new tired on the front end as of today. AND IT STILL SHAKES LIKE A DOG UNDER ACCELERATION OR A LOAD! Back out of the throttle and it goes smooth as silk. It is not as pronounced as before because the trans mount and the front engine mount were broken, but it is still there to the point that that you wouldn't want to drive it. I'm sure the shaking broke the two mounts. Remeber that this all came on at once! The car was going up a long grade, I pulled out to pass a truck and WAMMO it started shaking and I had to back out of it. I heard nothing break, pop, or anything when it started. If I had heard anything I would assume something broke and I would have gone looking for it. I had assumed that one of my axels gave up and that was the first thing I changed. I put the car in drive with the brake on and load the motor in the drive way and it shakes not a bit, nada , smooth wanting to pull thru my garage door. When your back on the road and accelerating shakes like a dog from 10 mph up thru when ever you back out of it at 50 ,70 or when ever. I hate to push a car over a cliff with brand new tires and motor mounts but I'm thinking about it AAAARRRRGGGGHHHHHHHH

[joe wilkerson]

I will investigate the injectors next, I think that one of them could be crapping out but idle fine and good at low RPM............(my drive way load test is at very low RPM) If that aint it its cliff time for sure LOLOL

[mfahey]

Just thinking out loud here but even though it is smooth in the driveway, there really isn't much load on it, unlike on the highway. I would lean towards a fuel delivery issue such as insufficient fuel pressure or as you mentioned, an issue with either a single injector or multiple ones. It could also be your coil.

[joe wilkerson]

yes , that coil was suspect, but the darn coil was expensive and I left that till later. The problem here is the way the front wheel drive system suspends the motor and tranny as a unit with the suspension, you can't really tell what is going on because of the rubber monted and suspended everything. If this was a rear wheel drive issue I think I would have had it fixed in no time, but the vaugness of the sysptoms after it gets to you from all that crap in the frontwheel drive system just makes you go crazy. Well, it makes me go crazy for sure YMMV LOL... Thanks for the tip, its raining today so I didn't get to the injectors. I might just go down and pay the price for a coil and plug it in since its the easier than messing with injectors thats for sure. One good thing about these lil problems ...ya get your whole car rebuilt while your fixing some simple thing that should have been found in a jiffy by a real mechanic,,,,,,,,,,,,,,,,,,,, thanks again

[TomQuick]

I too am really thinking that it is going to be a misfire for one reason or another. If it were related to the drive train / suspension, I wouldn't think that easing off the throttle would fix it. That it runs smoothly at speed, unless it is under load means something. The deciding factor seems to be how hard you are working the engine, and that points to power train, either weak spark, or poor fuel delivery. Have you verified correct fuel pressure yet? It seems that would cost less than throwing a coil at it, and even if it isn't the problem, it rules something out.

[joe wilkerson]

Its been busy with Xmas and I haven't found a local supply for cheap injectors so I went for the coil and changed that, you guessed it..... no difference. Locally the injectors are selling for $65-120 a piece (ouch).... on line I can get them for $25 bucks so I will order a set and give that a try when they get here after Xmas. Theres a nagging feeling that I have missed a huge clue in all of this. Changing all the tune up stuff was my natural next step when I found that the front end was really ok....... but tune up issues usually come on gradual................ my shake was immediate, just like you broke something , one min its ok and the next min it's "oh shit". I'm going to change those injectors but when I do and that doesn't help, my back is pretty much against the wall. I will be back to square one. All the front end stuff checked and replaced and then all the tune up stuff checked and replaced...... time to ponder. oh well lets see if those injectors will do the trick, its always the last thing you check , huh , but then thats always the way , why would you continue to check after you fixed it LOLOLO.. There is fuel pressure too, I'll look into that, I csn do that while the injectors are scampering from wherever. I did have a $700 fuel pump put in about 10,000 miles ago, I was in Phoenix and it went out. no tools or shade(it was summer time) and my motel was across the street from the dodge dealer. They helped me out with a ride to my job while the worked on my car and nabbed me for just a few bucks shy of $700.... love those dealers, huh!!!!

[joe wilkerson]

I never found a cheap place for injectors, but I did score on a set of 6 out of a car with 80Kmiles for $60 a set. I know I know they are not new and I'm replacing a "could be defective part" with a part of unknown part rather than replacing with a "known good"(new) injectors. My thinking is if he said the car was running fine and with 80K miles on them they are "probably good", so if I replace them with the new/used parts, even if the new/used parts are not perfect , the problem will at least change even if not cured. They will be here in a few days............I'll keep you posted.

PS ..... pulling the plenum and taking out the injectors was not a big job. about 25 mins and I had them on the bench......... the only issue is the tube to the EGR from the rear exhaust manifold, the heads of the two bolts are hidden below the throttle body but can be reached easily with a 10mm socket and a 4 inch extention. The rest of the hoses and nuts to take off are all pretty obvious. YOU DO NOT NEED TO TAKE THE THROTTLE BODY OFF OR THE BRACE THAT HOLDS THE ACCELERATOR CABLE. The TB, EGR all lift off with the top of the plenum and set to the side and at that point you are staring the injectors in the face. Don't forget to release the pressure in the system. to do this just take a couple of leads and hook to an injector and to 12 volts to turn on a injector. turn it on for 2-5 seconds at a time to let the injector squirt and relieve the pressure. The book said if you hold the injector on longer than 5 seconds you could damage them.

[bpaine]

Does the vibration seem like a bad gear in the rear of a rear wheel drive car? Like a slipping splein on a driveshaft? Or a split axle...If you get no engine breakdown standing still with a load on the engine, couldnt it be in the drivetrain???

[joe wilkerson]

Does the vibration seem like a bad gear in the rear of a rear wheel drive car? Like a slipping splein on a driveshaft? Or a split axle...If you get no engine breakdown standing still with a load on the engine, couldnt it be in the drivetrain???

The Vibration is really a shake. When you apply power or start up any grade, the front wheels feel like the are flopping back and forth as if the tie rods were made out of rubber! It truly felt like the wheels would fall off the car and the front suspension would fall on the gound. The feeling is still there but much lessened by changing the motor mounts. because the new mounts softened the shake it has to be the motor doing the shaking rather than the front end.. motor mount problems would not fix a suspension issue or make it less noticeable.... I'm still waiting for the injectors to get here ......arrrrgh

[joe wilkerson]

I had pretty well stopped working on it and was driving it here and there , not far from home but managed to run a tank of gas thru it with errands and trips to the store over the last two weeks, I was waiting for it to get worse, or maybe even and ------> pointing to the probem with the clouds parting and a ray of brillaint light. Nothing happened, never got any worse, naturally no ---->. I was setting it this afternoon after a trip to the store pondering over the problem. In my mind I was going over all that had been done. Another thing about the shake b4 and now... there never never was any metalic noise, no bump, no rattle , no ping, no kerphlump. just nada and the whole front end shaking. If it was a kaplank kaplank kaplank causing the shake or a whine or a grinding or a ping or anything it would lead me to a broken part. My thought processes told me that the problem is the same problem as it was before so it could not be anything that I had changed because what chance of two broken parts , bad plugs , etc would manifest itself in the same fashion. right? As I was setting in the car I decided to change the driverside front axle again. If I had never done anything to the car and felt this shake I would change the axle first just as I did when it first started. I found a new axle at the local Kragen and with much swearing(front end work is not my favorite thing to do) and 3 hours I swapped out the axle...................shaking gone!!!!!! It was the inner CV joint. I got my crow bar in there and was able to move it in a fashion that I thought it shouldn't be able to move.... not much , not falling apart, no tinkle just a side ways motion that told me it could flop when power was applied. after I got the axle on the ground there was no way I could feel any thing wrong, but with it in the spline and held tight I was able to tell it was a lil junkie. No failing boot or grease spitting out , looked perfect and had been on the car from AZ to CA and then about 500 miles til I parked it two years ago. The part failed in less than a 1000 miles and manifested it self in the same exact fashion as before. I guess the good news is I have new plugs, wires, cap , rotor, motor mounts, trans mount, front end inspected and aligned, and now since I had the front end apart , new brake pads too. (I marked the bolts and got the front end back where it belongs and do not need to realign... woo woo) So there is the end to a nasty saga of Trouble in "Dodge" City LOL. I think I was way over anal-izing the trouble. If it shakes like an axle change the MF, even if you had had it in there 2 miles, an axle shake is an axle shake ! JW

As far as the shake getting better after I changed the motor mounts, it did not isolate the problem engine from the suspension , what it did was re-postion the engine and now the CV joint was not working as hard and made less noise and vibration. when it got better after the motor mount change I spent way too much time working on the motor. once again if it shakes like an axle , change the darn axle!!! LOL

Thanks for all the replies and help

[TomQuick]

Good work, great to hear you got it figured out, and fixed, and now you should get many more miles of service from it.