5.3 need help!!
Thread Starter
Teching In
Joined: Mar 2009
Posts: 48
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5.3 need help!! 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
TECH Senior Member
Joined: Jun 2016
Posts: 22,290
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From: Central Cal.
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.
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Verdad Gallardo Thread Starter
Teching In
Joined: Mar 2009
Posts: 48
Likes: 1
5.3 need help !! 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.
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.
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
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...
Thread Starter
Teching In
Joined: Mar 2009
Posts: 48
Likes: 1
5.3 need help !! 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
Staging Lane
Joined: Feb 2017
Posts: 63
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From: Leola PA
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.
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.
You could also do a short block or crate motor.
Overhaul would be the least expensive.
Thread Starter
Teching In
Joined: Mar 2009
Posts: 48
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5.3 need help 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
Thread Starter
Teching In
Joined: Mar 2009
Posts: 48
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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?
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
DOD delete means cam, lifters, lifter trays, head bolts, head gaskets, and valley cover. Plus reprogramming and maybe a few odds and ends...
Last edited by G Atsma; May 22, 2018 at 06:57 PM.