1975 Dodge Sportsman RV

The oil pressure on my RV dropped to around 10-20 the other day while going uphill. I also noticed a slight knocking noise behind the accelerator pedal when I accelerated. Not sure what that was. Once it reached flat road the pressure slowly started to climb back to normal. I quickly parked it out of fear of it being something serious.

Normally I would see the pressure at 60 after starting and running the RV. Now I only see it climb up to 40. I checked the engine oil and it is past the full mark by about ... 1-2 quarts... perhaps? I have no car repair experience.

The other day after moving the RV about 10 blocks I came to a stop to park and after moving the trans to Parking, or while in Direct (Can't recall been so busy), the knocking noise started up again loudly. It has an automatic Transmission and a slight knock when putting it on Reverse.

Today while moving the RV we went to a slight down hill road, very slightly declined, and the pressure dropped to about 20. When we came upon leveled road the oil pressure slowly, very, very, slowly climbed back to around 25-30 ish. It did not climb any higher. Decided to park it.

The oil that was put last in the RV was 20 - 50 oil viscosity. 6 Quarts I believe which brings it to full. I don't recall the brand. We also put in a small amount of lucas oil stabilizer on top. Perhaps not the best idea as I think this brought the engine oil level above full. This was done around February. Also a couple of months prior to this we changed the fuel pump because we thought it had a torn diaphragm.

One Mechanic told me there is a very tiny leak on the rear main seal. Thinking on getting it fixed some day, but its really expensive to do so. I understand an oil pump change is extremely costly too. I just want to figure out what is the problem. Someone also mentioned it could be the powersteering pump.

Had a Mechanic do a tune up last year. That included the Oil, Filter, and Spark Plugs I believe.

1975 Dodge Sportsman
8 Cylinder Engine
5.2L <-- not entirely sure on this will have to double or triple check.

Not original owner, or first owner, and don't have the manual. Can't find it anywhere not even Ebay.

Need some help and suggestions on what can be done. I will also be looking into asking more mechanics on the issue. Forgot to mention that I barely use this RV. Most of the time it is parked and moved every 3 days for street cleaning. Not moving it much either. Just a couple of blocks.

A 75 Dodge probably has a 383 cubic inch V8. That would be 6.27 liters, but they didn't measure them in liters back then. A shop or parts store will know it as a 383.

How many miles on this beastie? It sounds as though both engine and transmission are old and tired.

Oil pressure fluctuations...it sounds like a case of just not enough oil.  But, since you say it is full, then another possibility is the oil pump, either mechanically in trouble or the sump pickup could be clogged, especially in this old of an engine.  I'm not familiar enough with the Dodge engines of that era (BTW, you could have a 360 ci, another common size then), so I do not know whether the oil pump has the gear driven off the camshaft or if the distributor has the gear and also drives the oil pump.  If the later, it could be a loose distributor, loose enough to allow the "straight slot like" connection with the oil pump to slip.  When changing engine load (accelerating or de-accelerating), the vacuum advance applies a rotational pressure on the distributor and might cause the distributor to "float" up and allow the connection to slip.  Of course, this is pure speculation as I do not know which drives what...just brainstorming.

A Dodge Sportsman is a van type (Class B)......It could very likely have a 318, which is 5.2 liter......The low oil pressure doesnt sound good. I would change the oil and filter and then see how it is....Also, dont over fill it, causes the oil to foam which can reduce pressure

I think you have gasoline contaminated oil.
Have your mechanic find where the gas is getting in your oil. It's either the carb or mechanical fuel pump, or both. Diaphram in fuel pump, or needle valve in carb. It's even possible for your carb to boil on shut down and empty the bowl into the engine oil.

One, two quarts overfull will be all in the back of the pan when going uphill. The crankshaft counterweights are whirling in the excess oil, thinned by gas, turning it to froth. Ya can't get much pressure out of froth. Pressure comes back slowly as froth settles. 40 psi oil is still acceptable. Fix fuel leak and change oil before driving it much further than a shop. Your engine may already have excessive internal wear from the thin oil and loss of pressure. With a little luck your lower than normal oil pressure will return close to what it was. Remember 40 psi is absolutely acceptable, 10 psi for each 1000 rpm is a general rule on gassers. Hope your not trying to wring 5000 rpm out that old iron.

Bill

Hi Everyone,

Wow thank you for all that input. I would guess that the general consensus at this point would be 1st: Change oil and oil filter. 2nd: Find gasoline Leak? I really do  appreciate the responses. I don't know much about the RV even though we have had it for about one year, so I went to look for some tags and took pictures.

http://i.imgur.com/QBDwLci.jpg
http://i.imgur.com/Blrrhl5.jpg
http://i.imgur.com/TII2fNi.jpg
http://i.imgur.com/GThrgSp.jpg
http://i.imgur.com/OQrVyRD.jpg
http://i.imgur.com/PnFrUEY.jpg
http://i.imgur.com/I2gaSV9.jpg

Code No: Ec4  Description: ENG 8C YL HCH AUTO 2BBL 360-2 04(If there is another number after this I cannot see it as the paper has stains).

The first picture is of the tag on the driver's door. There is some information there, but I am not sure how helpful it will be.

The second is of the tag under the RV/Van's hood. I think this one has the engine information on there.

The other pictures are of the Engine itself. The first looking at it down from the front after opening the hood. You can see one hose that runs from the radiator(?) to the engine. That hose I think needs to be replaced. It looks completely collapsed. Could this be part of the problem?

The next picture is of the engine. The newer looking parts are new and not the original. So I think one is called the coil and the other the distributor... cap? Also, the carburetor was rebuilt, but you can't see it here.

I was looking at this website: http://www.allpar.com/mopar/b-engines.html and it says that "The 'B' series wedge engine was introduced in 1958 with 350 and 361 cubic inch versions" and " Maintenance and repair were eased by the external oil pump, dry intake, and front-mounted distributor, along with an easily changed water pump." would it be possible that this engine right here has an external oil pump? If so, that would be a big relief. I was quoted on a price range of $2,000 - $2,500 +++ to replace the oil pump.

Also, it has a guide on how to find what type of engine your van has. I tried to look for numbers under the distributor cap, and I took a picture of it which is the last one, but I did not find anything. Just a number before near the transmission reading: OrO7

One thing I should also mention was that in the last picture you can see the little bell where the oil pump cable is connected. A mechanic had to adjust the clip so the reading in the oil gauge could work better. That was about 6 months ago. That was when the gauge went up to 60 (PSI?) while before that I believe it was always at 20. Though I don't recall if before or afterwards the gauge would move from those numbers.... Until now.

Sorry guys I hope it is of some help.

It's a 360 cubic inch(CI) 2 barrel(2 BBL). I think the fuel pump is on the drivers side near front of engine. 2 bolts, 2 fuel lines and a gasket. cheap ones are probably around $30 get a $50 one if you can. The collapsed hose is radiator overflow. not crucial but good to have.

Bill

Hi Gary,

I'm so sorry for no answering your question first. I was just so busy trying to gather all the pictures and reading in formation. When we got the RV it had 31## miles and right now it has 3531 miles. We really do not use it much other than to move it due to street sweeping and occasionally, like every 2 months, we might do 20 miles to visit someone then come back. The RV sure is a beauty, at least we think so!

Hi Poncho,

Yes, the RV is a Van type. It was made from the Dodge sportsman Van I believe.

Hi Driftless shifter,

The gasoline in the oil was a suggestion about six months or so ago. The guy suggested changing the gasoline pump (Broken Diaphragm?) so we paid him to do so. Went to the store with him and bought the pump then he came back and installed it. Changed oil and filter too. He said that when checking the oil it will still have some gasoline due to left overs, but on the next change of oil it should be good. Could it possibly be that the diaphragm on this pump broke also and is leaking gasoline? I mentioned to him the oil was over by about 1-2 quarts but he said "Don't worry that much won't cause any problems." So I said "Ok". He also recommended Lucas oil stabilizer on top.... Only a small amount which I believe it was like 1/4th of the small bottle, I don't recall the exact amount but it did not seem like much.

I should have just tried to change the oil myself at some point and made it so level would be right at full or slightly lower?

It is funny that you mention the carb because sometime after the RV was bought, I think 3 months into it, we had the carb rebuilt. Later on when we were told about the gasoline we spoke with the carb guy and mentioned that someone said it could be the carb or F.pump. The carb guy said it was not possible for the gasoline to get into the oil through the carb. Sang it like it was the gospel! So we just changed the fuel pump. Things went along pretty well, but I sometimes feel the over loaded oil pan along with thick 20/50 oil and the lucas oil did something to the RV.

On the very day the pressure dropped it was quite hot too. Not sure if that could have helped any damage.

"excess oil, thinned by gas, turning it to froth. Ya can't get much pressure out of froth. Pressure comes back slowly as froth settles. "

This sounds exactly like what is happening. I am hoping it is just that because the price quoted for the oil pump change is just out of my reach....

The person who drives the RV is my mother who loves the little thing. She drives pretty conservatively, almost like on egg shells sometimes, and never gets on the freeway with it. We really do not use it much. Sometimes we do about 20 miles out then back, maybe once a month or every 2 months. Move it every 3 days for street sweeping here in L.A. Sometimes we also spend the night in there and have a great time together. It is a nice experience . I am hoping the experience can continue on much further for sure. Mother says that she would not mind retiring to an RV at some point later in life. So, there are some big hopes along the way.

Out of curiosity you mentioned "10 psi for each 1000 rpm ", and I looked at a calculator which stated " If you want to convert a rotational speed to a linear speed, such as miles per hour, you need to know the diameter of the circle the object spins around. " when it mentioned the 'circle' it talking about the tire size?

Is there anyway to identify the name of the engine? I used to think it was a super red ram engine.

Your engine is not a Red Ram, that great engine was used back in the early 50's. You do have the 360CID engine, you know that from the tag you showed us and that most class C rv's from the 70's used them from 21' to about 26'. And you most certainly can get fuel in the oil from a carb that has a stuck float or just the fuel level set to high in side! If a mechanic is telling you no way for fuel to get into the oil from a carb don't ever go back there as he is a liar or know's so little about a carb you don't need that kind of trouble.
Your oil pump is in the oil pan and will not be your problem by how you talked about it. Pressures go away slowly with wear. Your oil level is one major problem that needs to be address by some one who knows what they are talking about for not only saving your engine but from a safety stand point, you have a bomb waiting to go off if you really have that much fuel in the pan!

Hi Guys,

Great, I won't pay him a visit any time soon. It is odd the carb guy did not know that. I brought up the subject more than once and every time he'd just say it was not possible. Funny because his shop said it had been open since 19XX something. By the way I was looking at a video online on how to change the mechanical fuel pump and it does not seem that difficult. Any advice? I am a little concerned about the fuel line spilling fuel from it. My guess is that if the pump is at a lower level than the tank the gas will just spill, but if it is at a higher level it shouldn't? Should I remove the battery while replacing the pump? It will be my first time doing something like this and other than some videos online I do not know what to expect. Any suggestions on tools for this? I will also do the oil and oil filter change since it looks to be ridiculously easy to do. Someone suggested running a magnet in the oil bucket to check for metal particles. Would this be advisable?

I apologize for the mix up on the engine I'm just a newbie when it comes down to this.

Oh, something I should mention: About 75% - 80% of the time when first starting the RV the alternator gauge tends to go from 0 to -12 or -25. When that happens the needle goes back and forth from 0 to -12 or -25 and the RV begins to, well, choke? I don't know the right term to use, so I apologize. I say choke because it sounds like the machine is about to shut off, and if I don't provide a small amount of acceleration with the accelerator pedal ... it does shut off! If I do provide a small amount of acceleration the Alternator Gauge moves to 0 or +12 or +25 depending on how much acceleration is provided. I usually try to aim for +12. After keeping it accelerated for about 3 to 5 minutes I can let go of the accelerator and the RV will purr smoothly with a steady +12 reading on the alternator gauge (Sometimes when it 'chokes' this way on start up the gentle acceleration feels, for a lack of better word, painful). No problems at all after that. I don't know why it does this or what could be the reason. I do notice that if it has been running, like being driven around or all warmed up, this type of issue does not come up when you start it again.

Plus I have noticed some water coming from the tail pipe. Not much and I think it might be only when first started. I'm just throwing this little bit out there just in case as I am unsure if that is normal.

Finally, we got the RV a new alternator about a year ago, and the Battery seems to get charged well enough, at least in terms of the car starting up.

I would disconnect the battery when working on fuel pump, just to be safe. You will likely spill a little gas. Make sure the loose cable is will away from battery terminal, maybe wrap it in a rag to avoid a spark

Alternator will fluctuate when you first start it...as long as it goes to +12 volts, you are good

As for the choking, it seems that your choke is set a bit too tight, just needs adjusting a bit

The water out the tailpipe is perfectly normal. It goes away as engine heats up

Tell that mechanic you want your money back or you're going to make a stink. When he "rebuilt" your carb he failed to fix or adjust the choke and high idle dashpot. And explain to him that either he didn't rebuild the carb at all or knows nothing about it in the first place. There are a couple different ways a carb can put gas in the oil.

The cold start symptoms, and the gas in the oil and the recent new fuel pump point directly to the carb being the problem. Unless the same "mechanic" did the fuel pump and did it wrong or not at all. You'll know if it was never done once you put your eyes on it, a newer one will look a lot newer than everything around it.

Spilling fuel.
The line that goes up to engine will only spill the small amount of gas that is in the line. Disconnect that one first, catch the gas in a small container.

RULE #'s 1, 2 and 3 working with fuel.
Disconnect battery.
No smoking under car.
Keep work light well clear of any dripping gas. If gas drips on a light bulb type it will pop, it will catch fire.

If both in and out lines are the same diameter find a bolt, drill bit, big nail, that will fit into the hose tightly.
The one that runs back to the tank will do as you fear. Lightly clamp some vice grips on the rubber line to squeeze it shut. Disconnect the line and stick the bolt, or whatever you found, into the hose, use the hose clamp to make a secure plug.  Remove vice grips. Don't fret too much about spilling a little gas. Just stop the leak and take a break while it evaporates. Gas lines always spill some.

The alternator is fine. The gauge fluctuations are another symptom of a poorly rebuilt carb. When the cold engine struggles to run it slows down below the alternators needed minimum speed to generate electricity, Feathering the gas pedal brings the speed back up and the alt starts charging again.

If you have the funds, look into buying a guaranteed rebuilt carb from an autoparts store.

RULE #1, when buying rebuilt parts.
Always pay the core charge and keep the core until new part is installed. You will most likely need something from the old part to install the new part. Tough lesson to learn the hard way! Return core for refund when done.

Don't be intimidated, The early-mid 70s Dodge was pretty simple, durable and reliable.

A tip for further study, nothing to do with current issues. Look into "1975 Dodge ballast resistor", and then keep one in the glove box. They're cheap.

Bill

Hi Guys,

Wow, thanks driftless shifter. I will see what I can do about the carb stuff, but the guy did the carb work almost 1 year ago. He only gave us a 3 month warranty. When I saw the carburetor it looks spanking new compared to the other items on the engine. Thanks for the pointers and I'll gather some drill bits for the hose. I will also look into the "1975 Dodge ballast resistor".

The fuel pump was done by another mechanic who was not the Carb guy. I was wondering, it looks like the hardest part about the Fuel Pump change is keeping the gear inside the engine on top while sliding the 'arm' of the fuel pump in. Any tips for that one part? Someone in a video suggested a screw driver stuck in there to keep that gear up. Then slide the fuel pump arm under neath. I don't want to break anything, so is this safe to do?

The gear inside the engine is called a 'Plunger'?
The arm of the fuel pump is called a 'rod'?

He also used aviation glue.... and only applied the glue to the pump where it meets the gasket. You don't have to apply it to other end that is on the engine side?

Out of curiosity what would happen if I put the rod on top of the plunger by mistake?

Last night I was looking at the fuel pump from the right tire and the area around the pump looks to be wet. I don't recall seeing any spills on the bottom of the RV, at least not on that side, where the fuel pump is. The other day I did see a little leak in the power steering pump. Could that be sign of a broken diaphragm?

Thank you all