Hiya everyone.

Quick one I hope. 2005 Dodge Dakota with the 4.7 V8 Magnum. (sounds impressive!)

It is running poorly, and while we where attempting to put it into a work space we noted the oil pressure light was flickering. Now to my ear it wasn't running that 'rough' to cause oil pressure drop? But maybe it was just rough enough.

It's got a dummy light installed. I hooked up a scan tool early this morning (very cold engine) and did a reading on the oil pressure and it was 'stuck' at something like 45.5 or 47.5.. The interesting part is that the pressure reading never changed. Now with a normal sending unit it should go up with RPM and drop down as the engine heats up and the RPM's reduce.

I'm already planning on pulling the sending unit out (it should be above the oil filter, correct?) And hooking up a manual gauge to it and seeing how good/bad the engine is. If the oil pressure once things get warmed up is very weak? We're going to stop on our project and that'll be that.... If the oil pressure is within tolerances we can proceed.

Question: Did Dodge use a "Dummy" sending unit like Ford uses? (Meaning the sending unit is a big fat liar and only reports a flat number unless the pressure drops below 7PSI....) or did Dodge use a real oil pressure sender and is sending the PCM a true oil pressure reading. Because if it's the latter? That would indicate the oil pressure sender is effectively 'stuck'.

Many Thanks!! I asked in my 'new member' post if I should dump every problem this truck has at once, or do it thread by thread. I figure I'll start slow and work through these issues.

S-

 

I mean, you can always check with a mechanical gauge to back it up. Not really sure about the accuracy of the "dummy" switches - the internet is full of BS so I hate speculating. Nothing wrong with double checking the pressure, just beware of firing up the parts cannon because some moron told you to.

Lotsa stuff can cause rough running. Most famously on these trucks is the battery and/or battery terminals. How is the air filter? How are the spark plugs? How is your fuel pressure? Is the TB clean? How's your PCV? She fire any other codes at you?

 

I would assume it is likely a sending unit that is only good for telling you that oil pressure exists rather than reporting a discrete value as that seems to be what most OEM's use.

 

Yep, I had the day off yesterday and spent time working with the engine.

It's a 'stupid on/off' switch. We removed the sending unit yesterday and I put my MAC transmission/oil pressure tester onto it. (one of the few tools I kept after my semi-retiring)

The engine might have 194k on it. Oil pressure looks decent. We had about 70PSI when cold. After it warmed up it settled down to about 50. Lowest it got was about 30 when it was moved in/out of gear and the engine coughed slightly. It does appear to have a very slight 'stick' to the pressure regulator in the oil pump. Upon rapid acceleration and decel, there's a noticeable "stick" with the gauge. Hard to describe, but most of the time it was a smooth uptick and down tick in oil pressure as expected. A couple of times the pressure seemed to 'hang' and then snap to a different spot on the gauge.

I've got 6qts of 10w30 full synthetic and a factory oil filter ready for it. (The loss of the "Fram" filter should do wonders to solve a few problem LOL)

The oil pan however? Wow.... What a crusted piece of Stupid cheap metal. (Thought I'd type something else, didn't you....) It's got some pretty thin areas. We're going to wire brush off the loose stuff and treat it with the rust converter and give it a paint job. If any areas peek through and we get any pin hole leaks, We've used the repair epoxy in the past with good results.

Only 'fail' happened with the radiator. I knew the radiator had a leak. It took almost a gallon to top it off for testing. (Our heat returned in the cab!!!! Amazing what having coolant will do!) My arm bumped into the left side of the radiator where the transmission line goes into it while installing the oil gauge. The entire assembly that holds the line just fell off. I told the wife: That explains why the transmission fluid is bright pink! The last owner crammed the fitting back into the radiator.

Also I think this guy dropped in several cans of stop leak. Almost a gallon of fresh coolant and after purging the air out of the system, it looked jet brown. It's getting a full dump and refill..

We've already picked up a used radiator for it. If it holds together? Great! Although I'll likely dump the internal transmission cooler in favor of an external unit.

S-

(Scratch one off the list!)

 

Nice. Well done. One thing that might help is to download the Factory Service Manual. It's in one of the stickies. It's for the 2005.

 

Absolutely! Which is interesting, as I also ordered in the "Haynes Jockey" manual as well.

Knowledge is power!

S-

 

Haynes Jockey...nickname for the normal Haynes manual? Or, something different?

Which is better Haynes or Chilton? Why?

 

Up to the mid 1970's, Chiltons were really good manuals. Not anymore. They may still have some basics as well as specs., but Haynes owns them now and Haynes is better for illustrations and details. As for the Jockey, I'm not familiar with that term.

 

Haynes and Chilton are pretty much on par with each other. Sadly they seem to be moving over to 'online subscription' for certain makes and models. eg: We have a 2010 Dodge Journey. Can't seem to find a hard copy of the manual. It's either spend money on a 'disc', or pay a subscription fee for access. Now if it's a highly detailed subscription designed for professional mechanics? No problem! But for a home user or DIYer.. Usually a hard copy with basic information is okay.

Regarding the phrase "Haynes Jockey". That one is a bit of a slam against some of the people that hang out (usually on YouTube) and come off like experts on every car ever manufactured. That's the downside about the internet and social media. Anyone can be anything they claim, but it only takes a few sentences to figure out they are full of 'nonsense'. So we affectionally call them "Haynes Jockeys"...

I never claim to be an expert on anything. There's always more to learn and all it takes is a open mind...and at times a closed mouth so you can hear :-) My own knowledge ends at about 1995 when I returned to college and then found myself managing video arcades. Been doing that for over 25 years now. But I still love tinkering with cars.

Have a Super Weekend!

S-

 

Now that I was not aware of.

Learning all the time!

S-