Loss of power in 88 caravan

[Future Murse]

Howdy all. My 88 caravan 6 cyl. has 165k miles. Since I bought it (35k ago), it's been a smoker - usually bluish smoke (oil burner?) That hasn't been a huge problem, it just has an appetite for oil. However, this is a sign of the dying phase and I think my car has died.

Now (this symptom happened suddenly,) when I go up a hill or exert the engine to accelerate, there is a distinct loss of power accompanied by a spraying/spitting sound. I think there's a belt squeal on top of this. The gas mileage has been cut in half. Other than that, everything else is the way it has been, except that the smoke may be a little more gray. I haven't noticed any contaminants in the oil.

Does this probably mean that my head gasket is gone? Or could it be simpler like a stuffed up fuel injector? Any help would be greatly appreciated - Thanks in advance!

[Cobra_Sam]

Originally Posted by Future Murse

Howdy all. My 88 caravan 6 cyl. has 165k miles. Since I bought it (35k ago), it's been a smoker - usually bluish smoke (oil burner?) That hasn't been a huge problem, it just has an appetite for oil. However, this is a sign of the dying phase and I think my car has died.

Now (this symptom happened suddenly,) when I go up a hill or exert the engine to accelerate, there is a distinct loss of power accompanied by a spraying/spitting sound. I think there's a belt squeal on top of this. The gas mileage has been cut in half. Other than that, everything else is the way it has been, except that the smoke may be a little more gray. I haven't noticed any contaminants in the oil.

Does this probably mean that my head gasket is gone? Or could it be simpler like a stuffed up fuel injector? Any help would be greatly appreciated - Thanks in advance!

Have you ever tried changing the oxygen sensor ? This has some control over your injectors and effects gas milage.
The spitting sound could be that the timing is not advancing under load or even that you have some carboned or oiled up plugs.
Good luck

[Future Murse]

I haven't tried changing the oxygen sensor before. I'll do some research to find where it is and how to change it. While I'm at it, I'll change the plugs. Thanks very much for the advice!

[Cobra_Sam]

Originally Posted by Future Murse

I haven't tried changing the oxygen sensor before. I'll do some research to find where it is and how to change it. While I'm at it, I'll change the plugs. Thanks very much for the advice!

I don't know for sure on the '88, but on my '92. the oxygen sensor is on the top side of the exhaust between the manifold and the catalytic converter. I have to jack mine up and put it on stands then climb under from the drivers side to get to it. Good luck, I hope this will help.

[Future Murse]

I finally received and replaced the oxygen sensor and the plugs. The plugs were pretty sooty and slightly eaten away - they were pretty old. The O2 sensor was sooty too, of course.

However, after these maintenance things that I should have done long ago, the symptoms are still there. Hissing and spitting under load. I guess my next tasks are changing the fuel filter and checking/replacing the vacuum hose(s). More long overdue maintenance. The fuel filter's no problem, just search and destroy the thing that looks like the new one. However, I have no idea where the vacuum hoses are, nor what they do, nor what I should be checking for - leaks, I guess. More help would be greatly appreciated.

Thanks again.

[Cobra_Sam]

Originally Posted by Future Murse

I finally received and replaced the oxygen sensor and the plugs. The plugs were pretty sooty and slightly eaten away - they were pretty old. The O2 sensor was sooty too, of course.

However, after these maintenance things that I should have done long ago, the symptoms are still there. Hissing and spitting under load. I guess my next tasks are changing the fuel filter and checking/replacing the vacuum hose(s). More long overdue maintenance. The fuel filter's no problem, just search and destroy the thing that looks like the new one. However, I have no idea where the vacuum hoses are, nor what they do, nor what I should be checking for - leaks, I guess. More help would be greatly appreciated.

Thanks again.

Check the knock sensor. This sensor tells the computer to advance the timing when the engine starts to strain under load.

[coryjl]

My question is on the plugs how eaten were the plugs...and do a compression check!!!

[Future Murse]

I don't have blades to measure the old plug gap - it didn't seem grossly wider than the new ones. There was minimal wear on the plugs, but they were all covered in carbon. My gas mileage is about 9mpg now, as opposed to 22-27 before. I changed that fuel filter for giggles and it had no effect (of course.)

I'm still at a loss as to what/where to look for any possible vacuum leaks. I also have never heard of a knock sensor before. I read some other posts which said that the "map sensor" also has a lot to do with fuel delivery. Are these sensors fairly accesible like the O2 sensor? That was pretty easy to find and change, but I'm growing impatient as this is my only set of wheels and I can't even leave town.

As far as the compression check that I haven't done...it always fires up right away, so I don't reckon that compression could be an issue. Without compression, it wouldn't start easily, right? Or if one cylinder was leaking badly, would it still fire right up?

Argh...I may have to visit the not-so-trusty mechanic soon if I can't fix her myself! Also contemplating putting her down for good.

[Cobra_Sam]

Originally Posted by Future Murse

I don't have blades to measure the old plug gap - it didn't seem grossly wider than the new ones. There was minimal wear on the plugs, but they were all covered in carbon. My gas mileage is about 9mpg now, as opposed to 22-27 before. I changed that fuel filter for giggles and it had no effect (of course.)

I'm still at a loss as to what/where to look for any possible vacuum leaks. I also have never heard of a knock sensor before. I read some other posts which said that the "map sensor" also has a lot to do with fuel delivery. Are these sensors fairly accesible like the O2 sensor? That was pretty easy to find and change, but I'm growing impatient as this is my only set of wheels and I can't even leave town.

As far as the compression check that I haven't done...it always fires up right away, so I don't reckon that compression could be an issue. Without compression, it wouldn't start easily, right? Or if one cylinder was leaking badly, would it still fire right up?

Argh...I may have to visit the not-so-trusty mechanic soon if I can't fix her myself! Also contemplating putting her down for good.

Is this a carburated model with a distributor ?

[coryjl]

well lol my father in law has a 351w ford engine that has about 275,000 miles on her and noticed power was pretty much gone so I did a compression test and needless to say he didnt have much. Yes a car will still start....may roll over really fast but it will start... Map sensor is a very good idead and lots of carbon on the plugs kinda points at a map sensor I had a blazer with a bad map sensor and would blow black smoke really bad....Is your van showing a check engine light??!?!?! I dont have my manual at my house to tell you where to look for the map sensor but goto autozone they should be able to show you! GL

[Future Murse]

fuel injection. no carburetion, just carbonation.

[Future Murse]

only occasionally does the check engine light come on.

[Cobra_Sam]

Originally Posted by Future Murse

only occasionally does the check engine light come on.

Still sounds like you are not getting the timing to advance, check the knock sensor.

[Future Murse]

Holy Moley!

I thought that everybody who was talking about their computer codes had some expensive gizmo that they hooked up to their PCM. Nobody told me that you just have to turn the silly thing on and off a few times a look at the flashing lights!

My codes are 13 and 51. So since I have a 13 without a 14, does that mean that the map sensor is probably good and it is probably a vacuum leak? Also, what the heck is a 51? My info says internal logic module fault for '84 turbo only. However, mine's '88 non-turbo. Help with code interpretation would be appreciated. At any rate, it does seem like a vacuum leak, which I still don't quite know how to pinpoint. Help with that would be good too. Thanks!

[Future Murse]

Almost forgot this old site I found. One of the most detailed on old caravan engines with lots of diagrams and pics. Very useful for those of us who don't own a manual.
http://robskorner.freehomepage.com/f...litrefaqs.html
Enjoy!