William Kisselstein

The 2500 has a hard start issue that the symptoms tend to point to either the regulator or pump, both a pain to change out.

But the oil pressure reads funky, very low, not consistent at the same speeds, it doesn't wiggle or wave around, just reads low, sometimes drops into the red if in gear and stopped. But not every time. I suspect a bad sender; I accidentally ran the 3500 low on oil once and it made a lot of not very good sounds, I would think if the 2500 really had low pressure it too would make unhappy sounds.

So before I go nuts on the fuel - because it runs great otherwise, idles fine, power is fine, mileage is about right - does this oil pressure sensor not let it start if it's not reading any pressure?

Because normally I have to crank it a few seconds, stop, crank again, and then it will start - hot, cold, unless it's been just a few minutes every time. I did change the evap purge solenoid and that improved the starting from when I first got it.

oldchevy

The low oil sensor will let you know you are low on oil before it makes any sounds. It came on for me once and no noise. I was able to add oil and had no problems. Your hard starting may also be a result of the check valve in the fuel pump being bad. It lets the fuel drain back into the tank when not running and it has to prime itself every time before starting.

William Kisselstein

Yes, I need to check the pressure; I bought an HF gauge set but between the cold and the 50-50 odds it's complete junk and will leak gas all over I haven't gotten to it. I should check the regulator too.

The 3500 I accidentally ran low on oil; it burns a fair amount and when it gets low the gauge will drop to nothing as you pull away from a stop. Eventually when too low it starts ticking and clattering. Didn't seem to hurt it any. After I knew what was going on I would just add a quart when the gauge started dropping.

This one sometimes drops right to nothing in gear foot on brake, and stays there. Other times, in gear foot on brake it's low but above the red zone. I noticed at roughly the same RPM the pressure it showed would vary a little with no apparent reason; not rapid motion on the needle but if say I slowed from 70 to 50 and back the needle would drop a little and stay there. Seems to be a common issue for the sender to go bad, or the screen on it to get clogged up.

The other possibility there is through bad regulator or leak under the plenum some gas has gotten into the oil. An oil change would probably answer if that's the problem, but here again it hasn't been conducive to laying on my back under there as when it does make it much over mid-30s it's rained. The oil looks fine on the stick, and was changed not too long ago as there's an oil change sticker showing it was due in December or at 132,500 or so miles.

I was frankly pleasantly surprised at how nice it drove though, I put a little over 300 miles on it Thursday and it was fine, normal power, cruising 70 or in mixed driving on two-lane roads, fuel mileage about 16 highway which is about right. The heat from it is good too.

canucklehead

Your 2500 is the 2002? Vortec 350's get oxifdation on the points inside the dizzy cap. Have you removed it and cleaned them and the rotor? Also, worn plugs have a wider gap which weakens the spark and causes hard cold starting.

I had a low oil pressure issue on my 2002 and I changed to high mileage oil and it improved things for sure. Also, make sure you use a good filter, wix, purolator, motocraft, mobil 1....not fram quaker state etc. You get a quality anti drain back valve in the better filters.

Doug D

I'd suspect a faulty or lazy oil pressure sensor if you are not hearing any knocking or odd engine sounds. A good way to confirm is to put a mechanical gauge on it. But oil pressure sensors are usually cheap. I'd just replace it. Had a '86 Chrysler LeBaron GTS where the oil pressure gauge began displaying low pressure readings. A new sensor solved the issue.

cablesplicer

I had the same trouble with my older 350 , changed the sender and that fixed it for awile. Now it's started swinging wildly but never to zero so i am not worried but since it's ''life time warrenty'' i will wait till spring to change it. The after market parts from china [slave laborer's] are not too good , lol. If your burning oil just pull the dip stick every morning and add if needed because running out of oil is ''never'' good and add's [i think] years of wear each time. One day i stopped to help 2 young girls who broke down because they ran out of oil and they told me they just waited for the oil light to come one as a sign they needed oil but they didn't carry any extra with them. I still wonder how much longer it ran untill it froze up completely.

William Kisselstein

I have two 2002s right now, a 2500 and a 3500.

I see the oil change sticker has "SYN" on it which I presume implies it has synthetic oil in it. Drove it today in the snow and just sitting at a light waiting I watched the gauge reading change even though the engine speed didn't.

My old '60 Pontiac would use oil too but on that one if I didn't check it often enough where it got low, it would start to run rough because there wasn't enough oil to fill the lifters. At least I assume that's what it was, because it ran rough until I added oil to it.

Well, hopefully whatever's wrong with the fuel system will last at least a couple more months. If it gets warmer I will pop the doghouse off and do the fuel pressure check.

jimmydriver

it could also be plugged up.

William Kisselstein

Discovered something interesting, perhaps the battery was failing in this.

I accidentally left the dome light on for about 10 hours and then had to leave it for the day. Jump started it that night and it was okay the next couple starts but Thursday when it was like 10' F for a high, it would only click. So I swapped batteries with the 3500, as that one you turn the key and like three seconds it's running.

Now, the 2500 starts better, no more crank three times, twice this morning and once it had been run, a long crank but start the first time.

Of course it also is warmer, mid-30s, so that may make a difference.