hpadder

Hi, my son and I bought a 9.7X Saab yesterday. We started it no smoke on start up it had a ruff idle. Took it for a test drive ran down the road well and shifts hard and smooth. Bought it drove 2&1/2 hours home and this thing smokes like crazy when we got here. Check engine light came on at idle put a scanner on it misfire#7. So I checked pcv hose and it is wet. I'm going to change the coil and look at the spark plug. What I don't know is if it's a DOD motor? Any help would be appreciated Thanks

G Atsma

If it's a 2005 or later, it has an LH6 5.3L in it which DOES have DOD, AKA Active Fuel Management. Blue or black smoke? Blue is oil, black is gas.

hpadder

So it's a 2007 and it is blue oil smoke and smell awful.

G Atsma

Valve guides &/or rings. How many miles?
The rough idle could be fouled plugs from the oil.

hpadder

115000 miles

G Atsma

I have to wonder how well maintained it was, as these engines routinely go 200K+ miles before anything goes wrong. Check the compression. If low, rings could be it. Otherwise could be valve guides.

hpadder

OK thanks have you ever seen one carboned up and the ring stick in the piston grooves?

G Atsma

Does that describe yours? If so, poor maintenance is the reason. Dirty air filter, oil not changed much, etc.

hpadder

Hi, can't say we just bought it but every indication would show by looking at it that they took great care of it. It's super clean. We will be digging in to it and I will post what we find.

Gasoholic

iTrader: (1)

Heck yeah I have. Gen 4s with AFM are well known for oil consumption issues.
The longer they run while burning oil the worse the carbon becomes.
GM has some TSBs about it.
Hopefully yours is something minor but soon as I hear cyl 7 misfire I get nervous.

G Atsma

They might have been meticulous in keeping it clean and cared for, BUT did not know some of the intricacies involved with the particular engine involved here. Probably more common than we want to think about...

hpadder

Holy cow I finally got to look at it. All plugs look terrible and #7 clean? So I did a compression test 140 all but #7. Good old number 7 has 0 so took valve cover off and the second rocker in from the rear is not moving? Bad DOD lifter is #7 a DOD cylinder or just a bad regular lifter? I guess a lobe could be bad on the cam also. Also all pcv tubes are full of oil and throttle body is VERY dirty I will guess that the intake is full of oil. Thoughts on this guys

G Atsma

Tear it down.

JimsNovaLS

The DOD cylinders are 1,4,6 & 7. You most likely have a collapsed DOD lifter. You'll be able to look at the cam lobe once the lifter is removed. If it looks okay (the same as the others) throw 8 DOD lifters in it and keep the oil changed. The 5.3 in my 06 Envoy works flawless at 140k and knocks out 25 mpg on the highway.

Gasoholic

iTrader: (1)

If it was me I'd do a complete overhaul and DOD delete. They make kits for this. Then have to reprogram the ECM.
You could also do a short block or crate motor.
Overhaul would be the least expensive.

cookseyb

I think WS6 Store has DOD delete kits..and anything else you need for the overhaul.

hpadder

Hey guys, just got the engine pulled down this weekend. Took a little longer to get around to then i thought. So my findings where the intake lifter was bad on #7 the plunger was pushed way down inside the lifter.the inside of the engine is very clean so i hope it was just bad luck for that lift. Also someone had been in to the engine not long ago because it had all fel-pro gaskets in it and when i pulled the internal head bolts they didn't seem tight at all in comparison to how tight the others where.so i think we will just do a full dod delete and have the ecu flashed. Thanks

hpadder

Hey guys, for you that have done a dod delete. I was told that the cam will need to be changed also. I knew i would have to reflash the ecu for the dod and afm but i thought you could leave the cam?

G Atsma

DOD delete means cam, lifters, lifter trays, head bolts, head gaskets, and valley cover. Plus reprogramming and maybe a few odds and ends...