96 2500 money pit

[imakedacookies]

I have done everything I can think of trying to fix a 96 Chevy k2500 with the 5.7 and 5 speed trans. It started off as a misfire issue then turned into a now power issue then stall anytime I pushed the gas. I've been throwing money at it like I'm in Vegas and it's gotten better but not right still.

Started off with new fuel pump and fuel filter as it seemed to not be getting fuel. Then I did the spider injectors, half were plugged so that helped. Then I thought it was timing and did a new distributor and cap. No change. Engine code occured for the mass air flow sensor, bam new one next day and no change. Decided to put in a new crankshaft sensor, that has helped the most. It acts normal when it starts, seems to be ok till you give it gas. It gives power better than before but still not enough to do much. Rpms wont go very high so I tried shifting early and all that did was top my speed at 20. The newest symptom was a wierd smell when I got out today. Not a typical burnt oil or coolant smell. Best I can describe would be bad bbq sauce. The last thing before I stop rambling is the old crankshaft sensor had what looked like thick milky oil on it when I took it out... I didnt think it would have anything like that on it.

Is this thing a lost cuase? I'm thinking it may have slipped timing, or the computer is bad. All I know is I cant afford to replace it and cant afford to keep throwing parts at it.

A mechanic looked at it but was stumped and he is the only guy that will come out to the boonies.

[Schurkey]

The truck is trying to tell you what is wrong, you're just not equipped to listen to it. Connect a scan tool, look at the data stream. The answer is almost certainly in the data. I'd especially be looking at coolant temperature, short- and long-term fuel trim, MAP sensor, and O2 voltage and cross-counts.

I'd also suggest checking fuel pressure You've already stuffed in a pump and filter, but you might not have proper voltage to the pump resulting in low pressure.

Wouldn't hurt to try a cylinder-balance test to locate dead/weak cylinders, and a compression test and/or cylinder leakdown test of any weak cylinders (or just do all of them.)

[maxwedge]

Another thought here is a partially blocked cat convertor, or even a internal muffler failure,both pretty easy to check.

[imakedacookies]

Fuel pressure is good according to the the guy that's been helping me. The codes that pop up are o2 sensor, cranshshaft sensor, map sensor, and misfire. I can try a o2 sensor but I really dont think that could cuase these issues. I have had a suspicion that its losing compression so maybe it finally just gotten that bad. I'll need to tow it to a bigger shop, I use a farm shop and we dont have all the fancy tools. I also found a motor on craigslist for pretty cheap. It's the same only 1 year newer and has a auto trans. Would it bolt up and be the same to swap with the one I have now? The new motor has 140k miles unlike mine with 235k

[Schurkey]

Originally Posted by imakedacookies

The codes that pop up are o2 sensor, cranshshaft sensor, map sensor, and misfire

You have bad enough misfire, you'll have crankshaft speed variations (Crank sensor), the engine vacuum will be erratic (MAP sensor), you'll blow an entire cylinder's worth of fuel out the exhaust valve un-burned (False-lean O2 readings).

You need to examine the data stream. Or have someone else examine the data stream.

Originally Posted by imakedacookies

I have had a suspicion that its losing compression so maybe it finally just gotten that bad.

So test the compression.

Originally Posted by imakedacookies

I also found a motor on craigslist for pretty cheap. It's the same only 1 year newer and has a auto trans. Would it bolt up and be the same to swap with the one I have now? The new motor has 140k miles unlike mine with 235k

You COULD need a new/different engine. It's possible.

You'll feel really silly if you change the engine and still have the same problems, though.

[imakedacookies]

I really need to take it to a shop but it will need to be towed and my other big pickup is down with a bad lift pump and my half ton cant pull that much. What else can I see from the data stream? I listed all the codes it threw but I dont know what else to look for. Any thought on the sticky milky oil on the old crank sensor that I took out?

[777stickman]

Milky oil could be coolant contamination. What does the dip stick look like? What do the plugs look like? Is it loosing coolant? As mentioned, do a compression test when you have the plugs out.

If you get another engine make sure to get the PCM that goes with it.

You also need to list code numbers or DTC's not just a description!!

[imakedacookies]

It does lose coolant but it's a leaky radiator. The dipstick never had any milky color but it does have a small amount of metal shavings. Not anything exesive but still not good I know. It loses oil at a decent pace when it's being driven so maybe that's why I've never seen signs of coolant in the oil. Compression test will need to be done at a shop with more tools. As far as codes it's the other guy at the farm that's pulled them from the computer and he just said what they said. Never told me the actual codes. I'll see if he can get his scanner and check again.

[imakedacookies]

Got my big pickup fixed so the good ole Chevy is going to make a trip to a shop on a trailer in the next week or 2. I'll let you know what they say for future references...

Side note I did see an old thread saying a bad ground to the backside of the cylinder head could cause symptoms like this. I'll check it out before I take it to a shop but do you think this could be a possibility? The thread said something like if that ground is bad it could cause issues with the computer and honestly I dont think there is anything mechanically wrong with it so could that fit the bill? It's pretty weird that between me and the farms mechanic and all the other very knowledgeable people that I work with for us to not figure something like this out. I can replace any part just hard to diagnose the problem sometimes.