Lost power? Need Help with why.
#11
08-26-2019, 09:45 PM
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#12
08-26-2019, 10:12 PM
Interesting. What should I be getting? And would it make that much difference? I dont think it's worth tearing into to do rings. I got it on trade for 1500 worth and it's pretty rusty. Also what should the plenum look like? There's no oil pooling but it is a little dark like its seen oil right in the center. Not sure if i should replace that either? Think I'll try some additive products first. Any recommendations? Lucus oil is my first thought.
Also previous owner is a friend and she tells me it had head gaskets done a few years ago at a shop. One side was burning coolant and no longer is. I assume they would do both sides? Not sure why they didnt do plenum at that time but maybe they did gasket for it? Not sure.
#13
08-26-2019, 10:18 PM
A lot of shops simply aren't aware of the plenum issue, so, don't check it.
SOME oil on the bottom is normal, generally it gets burnt onto the bottom of the intake, in a nice spray patter from where the PCV valve hose come in.
Your compression numbers are all within acceptable range, HOWEVER, the fact that they all jump almost 30 lbs on the wet test is a sure sign the rings are going.
Towing your 1500 pound trailer with O/D on is likely OK, towing the 4000 pound boat with O/D on most certainly is not. That'll smoke your trans......
Try this test. Unplug hose from PCV valve, plug the hose. On the other side, the vent hose goes to the air box. Pull it off, and plug that one as well. Take off the oil fill cap. Start engine. Stick your hand over the oil fill cap, you should feel a breeze coming OUT, if there is still vacuum there, then the plenum is blown, and that is at least part of your lack of power problem. Trouble is, blown plenum leads to fouled O2 sensors, and clogged cats. Hence, NO power...... and you get the symptoms you describe in your first post. If the plenum ISN'T blown, try simply disconnecting the O2 sensor. (that'll set a code) See if it drives any better. If it doesn't, remove the O2 sensor from the exhaust, go for a drive. (this will also set an O2 code, and it'll be loud......) Run better yet? The cat is clogged. No difference? Might be time for a tuneup, and timing chain.
SOME oil on the bottom is normal, generally it gets burnt onto the bottom of the intake, in a nice spray patter from where the PCV valve hose come in.
Your compression numbers are all within acceptable range, HOWEVER, the fact that they all jump almost 30 lbs on the wet test is a sure sign the rings are going.
Towing your 1500 pound trailer with O/D on is likely OK, towing the 4000 pound boat with O/D on most certainly is not. That'll smoke your trans......
Try this test. Unplug hose from PCV valve, plug the hose. On the other side, the vent hose goes to the air box. Pull it off, and plug that one as well. Take off the oil fill cap. Start engine. Stick your hand over the oil fill cap, you should feel a breeze coming OUT, if there is still vacuum there, then the plenum is blown, and that is at least part of your lack of power problem. Trouble is, blown plenum leads to fouled O2 sensors, and clogged cats. Hence, NO power...... and you get the symptoms you describe in your first post. If the plenum ISN'T blown, try simply disconnecting the O2 sensor. (that'll set a code) See if it drives any better. If it doesn't, remove the O2 sensor from the exhaust, go for a drive. (this will also set an O2 code, and it'll be loud......) Run better yet? The cat is clogged. No difference? Might be time for a tuneup, and timing chain.
#14
08-26-2019, 11:04 PM
A lot of shops simply aren't aware of the plenum issue, so, don't check it.
SOME oil on the bottom is normal, generally it gets burnt onto the bottom of the intake, in a nice spray patter from where the PCV valve hose come in.
Your compression numbers are all within acceptable range, HOWEVER, the fact that they all jump almost 30 lbs on the wet test is a sure sign the rings are going.
Towing your 1500 pound trailer with O/D on is likely OK, towing the 4000 pound boat with O/D on most certainly is not. That'll smoke your trans......
Try this test. Unplug hose from PCV valve, plug the hose. On the other side, the vent hose goes to the air box. Pull it off, and plug that one as well. Take off the oil fill cap. Start engine. Stick your hand over the oil fill cap, you should feel a breeze coming OUT, if there is still vacuum there, then the plenum is blown, and that is at least part of your lack of power problem. Trouble is, blown plenum leads to fouled O2 sensors, and clogged cats. Hence, NO power...... and you get the symptoms you describe in your first post. If the plenum ISN'T blown, try simply disconnecting the O2 sensor. (that'll set a code) See if it drives any better. If it doesn't, remove the O2 sensor from the exhaust, go for a drive. (this will also set an O2 code, and it'll be loud......) Run better yet? The cat is clogged. No difference? Might be time for a tuneup, and timing chain.
SOME oil on the bottom is normal, generally it gets burnt onto the bottom of the intake, in a nice spray patter from where the PCV valve hose come in.
Your compression numbers are all within acceptable range, HOWEVER, the fact that they all jump almost 30 lbs on the wet test is a sure sign the rings are going.
Towing your 1500 pound trailer with O/D on is likely OK, towing the 4000 pound boat with O/D on most certainly is not. That'll smoke your trans......
Try this test. Unplug hose from PCV valve, plug the hose. On the other side, the vent hose goes to the air box. Pull it off, and plug that one as well. Take off the oil fill cap. Start engine. Stick your hand over the oil fill cap, you should feel a breeze coming OUT, if there is still vacuum there, then the plenum is blown, and that is at least part of your lack of power problem. Trouble is, blown plenum leads to fouled O2 sensors, and clogged cats. Hence, NO power...... and you get the symptoms you describe in your first post. If the plenum ISN'T blown, try simply disconnecting the O2 sensor. (that'll set a code) See if it drives any better. If it doesn't, remove the O2 sensor from the exhaust, go for a drive. (this will also set an O2 code, and it'll be loud......) Run better yet? The cat is clogged. No difference? Might be time for a tuneup, and timing chain.
#15
08-27-2019, 09:06 AM
On high mileage motors, anything over 100 is considered "OK"....... So far as I am concerned, when you are getting down that low, it's time for a rebuild. The engine may still run fine, but, it is most certainly going to be down on power.
#16
08-27-2019, 11:28 AM
#17
08-27-2019, 10:15 PM
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After doing the above test you stated heyyou, I couldn't feel a breeze or a vacuum. It felt no different to me. However I did dump is some engine restorer, and re-gap the plugs which were all .005 of an inch off, and after resetting my codes my 02 sensor code has not returned. I will be driving it for a few days and redoing the compression tests to see where I'm at as I've seen this product work well. I still am not sure about the plenum and whether or not I should replace it.
#18
08-31-2019, 04:39 PM
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Well I havent had much time to drive the truck but i did put in a little under 50 miles again under 50 miles and these are the results on the passenger side bank front to back. DRY
145, 140, 140, 145
I didnt have time to check the driver side today but I would say pretty impressive. My 02 code did return however. I'm also considering changing the MAP sensor out as it's never been done in at least the 3 years me and my buddy have collectively owned it. Any thoughts on that?
145, 140, 140, 145
I didnt have time to check the driver side today but I would say pretty impressive. My 02 code did return however. I'm also considering changing the MAP sensor out as it's never been done in at least the 3 years me and my buddy have collectively owned it. Any thoughts on that?
#19
09-01-2019, 08:59 AM
Well I havent had much time to drive the truck but i did put in a little under 50 miles again under 50 miles and these are the results on the passenger side bank front to back. DRY
145, 140, 140, 145
I didnt have time to check the driver side today but I would say pretty impressive. My 02 code did return however. I'm also considering changing the MAP sensor out as it's never been done in at least the 3 years me and my buddy have collectively owned it. Any thoughts on that?
145, 140, 140, 145
I didnt have time to check the driver side today but I would say pretty impressive. My 02 code did return however. I'm also considering changing the MAP sensor out as it's never been done in at least the 3 years me and my buddy have collectively owned it. Any thoughts on that?
MAP sensors are pretty reliable. But, they are not really expensive either......
#20
09-01-2019, 11:10 AM
Champion
I was reading your descriptions and thinking (ow, ow, ow, now my head hurts 
) and when I saw the truck was "rusty" I wondered how the undercarriage looks. After driving, do any of the wheels, especially the front ones, seem overly warm or even hot? I'm not saying you DO have dragging brakes, but I'd check it. If you don't have one, get a remote infrared thermometer. You can read the wheel temperature and it's useful for checking for a dead cylinder too. The exhaust manifold by that cylinder will be cooler than the rest of the system.
) and when I saw the truck was "rusty" I wondered how the undercarriage looks. After driving, do any of the wheels, especially the front ones, seem overly warm or even hot? I'm not saying you DO have dragging brakes, but I'd check it. If you don't have one, get a remote infrared thermometer. You can read the wheel temperature and it's useful for checking for a dead cylinder too. The exhaust manifold by that cylinder will be cooler than the rest of the system.