96 850 N/A Running rich, white smoke, no codes

crisnumbertwo · Post by **crisnumbertwo** » 17 Aug 2015, 22:17

Hello all,

I have spent all day searching this and other forums for answers to my problem, but nothing has been satisfactory.
My car (~154,000 miles) has always had a rich smell from the exhaust, but starting yesterday it has become much more pungent, and was accompanied by black smoke and soot, and a small amount of water.
I went though all the accessible vacuum lines, and replaced a couple, because that is what many people said to do. The black smoke, soot, and water went away by the time the engine was at operating temperature, but there is still white smoke and a very strong fuel smell from the exhaust.
I changed the PCV system a couple of months ago, along with spark plugs and wires, ECT, and thermostsat.
There are no codes showing up, apart from the P0410 that showed up a couple months ago, but hasn't popped up in a couple weeks.
I checked fuel pressure, and it was at ~44psi.
I unplugged the MAF, and the car ran worse, with a very erratic idle.
I have a slight bounce in RPM while in D and stopped, along with the strong emission smell that is consistent throughout trips.
It seems that gas mileage has suffered at the same time, and I went through a quart of oil in several hundred miles of driving.
From what people say, I am thinking it is O2 sensors, but they are expensive, and I have seen many people say they still had the problem after changing them.
I have seen one person recommend looking at the intake manifold gasket for leaks with water/WD40/intake cleaner, which I think will be my next step.
Another non-Volvo person suggested the water pump.
The main reason I am posting is because there are no codes, but something is definitely going on, and it suddenly started.
I have yet to see a definitive answer, and I'm hoping someone has something new to add (most posts I have seen were from several years ago).

As usual, any and all suggestions are appreciated. Thanks for your time.

Post by **abscate** » 17 Aug 2015, 23:55

Start with a compression test in the motor to see how the internals of the engines are holding up

Report dry and wet ( with oil) measurements

During test, pull plugs and post a pic of the 5 plugs up close on the plug ends

crisnumbertwo · Post by **crisnumbertwo** » 18 Aug 2015, 00:04

abscate-- will do. One thing though, what does "Robots dry and wet ( with oil) measurements" mean? I am fairly ignorant in this field. Thank you.

Post by **abscate** » 18 Aug 2015, 04:44

Sorry , spell check error.

Report wet and dry compression

Post by **scot850** » 18 Aug 2015, 15:16

OR, to add to this, DRY is carry out a pressure check on each cylinder without adding anything to the combustions chambers.

Wet: Add some engine oil to the cylinders and re-check the pressure checks on each cylinder. The theory is that the dry test tells you if you have and pressure loss in a cylinder, the WET test allows the oil to ''temporarily' seal any losses of pressure past the piston rings, but if a valve is leaking, then the pressure will stay low. The difference between the 2 helps us to help you determine the next stage to go to.

With all the tests, remove all the spark plugs before starting pressure testing.

Neil.

Post by **abscate** » 18 Aug 2015, 15:30

When we look at the plugs we can tell if it's an engine problem or isolated to a cylinder or two

crisnumbertwo · Post by **crisnumbertwo** » 18 Aug 2015, 20:12

So it seems I have nothing but bad news at the moment.
Attached is a picture of one spark plug, but it looks like all the rest, with very thick black buildup.
I rented a compression tester, watched a video by Robert DIY, and went through the process from my Chilton. The tester read zero pressure, but would make a loud chirp with every crank on every cylinder. I am assuming the tester is releasing pressure, not building it up to read.
This is where I am at the moment, will see if they have a different tester, or go somewhere else for one.
Very disheartening thus far.
Thanks for your help so far guys, I will keep at it.

Post by **erikv11** » 18 Aug 2015, 21:04

So far, all you have is that it is running rich. Don't despair!

When you say no codes, are you checking them with the OBD reader or just looking for the CEL? Does the bulb work?

crisnumbertwo · Post by **crisnumbertwo** » 18 Aug 2015, 21:27

I have checked with my OBD, and it does not list any codes. I have the occasional P0410 (secondary air pump), but that shouldn't matter with this, right?
So got a new tester, and only did a dry run, since it is getting late, and this test is probably irritating people already.
DRY (psi)
1-154
2- 135
3- 110
4- 115
5- 127
From what I have seen, these are extremely low. I'll note: the car is on slightly unlevel ground, tilting to the back; oil might be slightly low. Both of these might mess with compression, right?
I will do the testes again tomorrow, on level ground with topped oil.
Thanks for your patience and advice.

Post by **erikv11** » 18 Aug 2015, 22:58

Agreed, the p0410 shouldn't matter.

Those numbers are low but not bad for a first run, the fact that they are all low suggests that another test tomorrow with all the ducks in a row could possibly give numbers that are ok.

If you can, take the car for a drive before you run the test tomorrow, so that the engine is warm. This makes it tricky getting the hot spark plugs out but is the best way to go. Be sure to pull the fuel pump fuse so that it doesn't send fuel into the cylinders, that can give falsely low compression numbers. I like to unplug the coil wire too, so there are no stray sparks from the wires. Level ground is not important, I often do this test with the car in the slanted driveway.

And finally, crank it until you hear 6 or 7 turns of the engine, until the needle stops bouncing up, before you stop. Basically see how high the needle can get. But no more than say 8 cycles.