My 07 Denali XL 'build'/Check Engine Lights/Questions

[breds2k]

I do have an oil pressure gauge, but was unsure what the actual number is. Im at 13 psi at 538 RPM (seems low to me??) with the engine fully up to operating temp etc.

^^^ Im at 45-50 psi @ idle in my 2007 Escalade (which doesnt have a gauge) thats so annoying that denali's have them but 07-08 escalades dont. Either way 13 psi is going to become problematic. Change the pickup tube o ring and report back. Oil pump is something guys do when they go all out on the top end built/cam swap as you are taking the top half off the engine, removing VVT in most cases and then its far easier to get to and if i was doing all that on a 3rd gen truck with mileage id 100% do a mellings high flow pump.

 

[carrmann]

What should I be idling at Rpm wise stopped and in drive? I'm seeing roughly 540 rpm, seems low to me? cruising down the road at 1000rpm its at 22 ish psi (havent hooked scanner up when driving to get exact numbers).

 

[carrmann]

Getting ready to order parts.

Cam position sensor, 02 sensors. Can i use a parts store or do i need to order gm parts? If so any suggestions on where to get them? Also new gas cap.

For the oil pickup tube oring, where can i get that and what other parts/gaskets do i need besides it to get it going? Time to fix this thing

 

[carrmann]

Replaced my gas cap with a new AC Delco one for the P0455 code (and because sometimes it spun instead of clicking when tightening). Code went away for a bit, but then I got a 'tighten gas cap' message, then a p0455 gross leak/no flow message. It didn't say the gross leak/no flow message before I don't believe.

Any ideas?

Anyone have a part # for the melling pickup tube o-ring?

 

[JB_TravelTech]

Carrmann,

Hey man, I stumbled upon your thread here and decided to finally join the forum so I can give you my feedback on this.. I'll explain the stalling issue that I fixed on my denali.

I read the first couple posts and replies, and skipped down to your most recent posts so I may be repeating what someone has already said.

I recently bought an 07 Yukon Denali.. the seller disclosed that it stalls when at operating temperature randomly. He had a shop try to fix problem, they replaced fuel pump and who knows what else but was still stalling. As we talked about what the cause could be, he mentioned forums and some people were saying "just change the oil" to fix the stalling issue... we had a little laugh about it as to say it's obviously not the fix.

I drove it home the next day, was supposed to tow it but decided to take my chances first, drove it very light on the throttle, made it all the way to the back lane of my house where it finally stalled and would not start.. I checked fuel pressure, had plenty and still no start. Scanned it and got the code you mentioned "camshaft position timing advanced"(I forget the actual code number and description as I type this).. spent that night online, and by the end of it I read and was convinced by a few posts to change the oil.

Then it all clicked in the next morning, took a while to remember that the 6.2 that started in these trucks in 07 were built with VVT. The vvt cam phaser that is bolted onto camshaft operates using oil pressure to advance/retard the timing during acceleration/deceleration. Your engine with the low oil pressure cannot operate the cam phaser properly.. accelerate, oil pressure goes up, cam timing advances, decelerate rpms go down, cam phaser does not adjust timing properly, engine stalls.

I changed the oil, used 5w30 synthetic and lucas oil stabilizer synthetic, hasn't stalled once since. My oil pressure warm sits around the "quarter" mark, and climbs to the half way mark on acceration, not sure the actual number, haven't bothered to check.

So.. these early engines I hear may have had cam bearing issues, they wear, lowering oil pressure, and just general wear of the engine will have the oil pressure lower than when fresh/new. It's plenty of pressure to lubricate the engine in general, but not enough to operate the VVT properly. And yes the oil pump pickup tube o-ring can be an issue. I worked at and engine shop years ago, a shop we sold a reman 6.2 used the original pick up tube and didnt bother to change the o ring. That engine had super low oil pressure, we said no way its from our workmanship, tight clearances and "spin tested" before being shipped. We asked about the pick up tube and o ring, they admitted didnt change it, we said it's gotta be that, they r&r'd it and sure enough it was crusty like a cheerio.

You could run a 10w30 oil with lucas and it would be just fine, no harm in using that weight oil even though the oil cap says 5w30 and thats what recommended.. 10w40 would even be fine.. which I say would be equal to running w30 with lucas. Or stick the 5w30 with lucas like I did and it's working for me.

Well I'll leave it at that for now considering it's a long write up I just whipped up at 1:30am.. looking forward to being part of the forum from this point on..

Let me know what you think!

 

[donjetman]

Replaced my gas cap with a new AC Delco one for the P0455 code (and because sometimes it spun instead of clicking when tightening). Code went away for a bit, but then I got a 'tighten gas cap' message, then a p0455 gross leak/no flow message. It didn't say the gross leak/no flow message before I don't believe.

Any ideas?

Anyone have a part # for the melling pickup tube o-ring?

When I changed the pickup tube o-ring on our 07 Denali 6.2 I used Felpro# 72401.
When I changed my gas cap I used AC Delco# GT330.

 

[carrmann]

Carrmann,

Hey man, I stumbled upon your thread here and decided to finally join the forum so I can give you my feedback on this.. I'll explain the stalling issue that I fixed on my denali.

I read the first couple posts and replies, and skipped down to your most recent posts so I may be repeating what someone has already said.

I recently bought an 07 Yukon Denali.. the seller disclosed that it stalls when at operating temperature randomly. He had a shop try to fix problem, they replaced fuel pump and who knows what else but was still stalling. As we talked about what the cause could be, he mentioned forums and some people were saying "just change the oil" to fix the stalling issue... we had a little laugh about it as to say it's obviously not the fix.

I drove it home the next day, was supposed to tow it but decided to take my chances first, drove it very light on the throttle, made it all the way to the back lane of my house where it finally stalled and would not start.. I checked fuel pressure, had plenty and still no start. Scanned it and got the code you mentioned "camshaft position timing advanced"(I forget the actual code number and description as I type this).. spent that night online, and by the end of it I read and was convinced by a few posts to change the oil.

Then it all clicked in the next morning, took a while to remember that the 6.2 that started in these trucks in 07 were built with VVT. The vvt cam phaser that is bolted onto camshaft operates using oil pressure to advance/retard the timing during acceleration/deceleration. Your engine with the low oil pressure cannot operate the cam phaser properly.. accelerate, oil pressure goes up, cam timing advances, decelerate rpms go down, cam phaser does not adjust timing properly, engine stalls.

I changed the oil, used 5w30 synthetic and lucas oil stabilizer synthetic, hasn't stalled once since. My oil pressure warm sits around the "quarter" mark, and climbs to the half way mark on acceration, not sure the actual number, haven't bothered to check.

So.. these early engines I hear may have had cam bearing issues, they wear, lowering oil pressure, and just general wear of the engine will have the oil pressure lower than when fresh/new. It's plenty of pressure to lubricate the engine in general, but not enough to operate the VVT properly. And yes the oil pump pickup tube o-ring can be an issue. I worked at and engine shop years ago, a shop we sold a reman 6.2 used the original pick up tube and didnt bother to change the o ring. That engine had super low oil pressure, we said no way its from our workmanship, tight clearances and "spin tested" before being shipped. We asked about the pick up tube and o ring, they admitted didnt change it, we said it's gotta be that, they r&r'd it and sure enough it was crusty like a cheerio.

You could run a 10w30 oil with lucas and it would be just fine, no harm in using that weight oil even though the oil cap says 5w30 and thats what recommended.. 10w40 would even be fine.. which I say would be equal to running w30 with lucas. Or stick the 5w30 with lucas like I did and it's working for me.

Well I'll leave it at that for now considering it's a long write up I just whipped up at 1:30am.. looking forward to being part of the forum from this point on..

Let me know what you think!

I thought the same thing, as when the oil pressure at idle drops down to like 10 ish psi (depends on rpm), it starts idling rough before dying.
I read this post today, after I had the truck setup to change the oil, which I'm doing in the AM. Still planning on doing the oil pickup tube o ring unless i see a drastic improvement in oil pressure.
Thank you for your comments, and your personal experience. I hope mine is the same!

 

[carrmann]

When I changed the pickup tube o-ring on our 07 Denali 6.2 I used Felpro# 72401.
When I changed my gas cap I used AC Delco# GT330.

Thank you, that is the gas cap I got. So, something else is wrong with my evap stuff.
Thank you for the part # on the oring, I've searched a few times and found multiple part #s.

 

[carrmann]

Carrmann,

Hey man, I stumbled upon your thread here and decided to finally join the forum so I can give you my feedback on this.. I'll explain the stalling issue that I fixed on my denali.

I read the first couple posts and replies, and skipped down to your most recent posts so I may be repeating what someone has already said.

I recently bought an 07 Yukon Denali.. the seller disclosed that it stalls when at operating temperature randomly. He had a shop try to fix problem, they replaced fuel pump and who knows what else but was still stalling. As we talked about what the cause could be, he mentioned forums and some people were saying "just change the oil" to fix the stalling issue... we had a little laugh about it as to say it's obviously not the fix.

I drove it home the next day, was supposed to tow it but decided to take my chances first, drove it very light on the throttle, made it all the way to the back lane of my house where it finally stalled and would not start.. I checked fuel pressure, had plenty and still no start. Scanned it and got the code you mentioned "camshaft position timing advanced"(I forget the actual code number and description as I type this).. spent that night online, and by the end of it I read and was convinced by a few posts to change the oil.

Then it all clicked in the next morning, took a while to remember that the 6.2 that started in these trucks in 07 were built with VVT. The vvt cam phaser that is bolted onto camshaft operates using oil pressure to advance/retard the timing during acceleration/deceleration. Your engine with the low oil pressure cannot operate the cam phaser properly.. accelerate, oil pressure goes up, cam timing advances, decelerate rpms go down, cam phaser does not adjust timing properly, engine stalls.

I changed the oil, used 5w30 synthetic and lucas oil stabilizer synthetic, hasn't stalled once since. My oil pressure warm sits around the "quarter" mark, and climbs to the half way mark on acceration, not sure the actual number, haven't bothered to check.

So.. these early engines I hear may have had cam bearing issues, they wear, lowering oil pressure, and just general wear of the engine will have the oil pressure lower than when fresh/new. It's plenty of pressure to lubricate the engine in general, but not enough to operate the VVT properly. And yes the oil pump pickup tube o-ring can be an issue. I worked at and engine shop years ago, a shop we sold a reman 6.2 used the original pick up tube and didnt bother to change the o ring. That engine had super low oil pressure, we said no way its from our workmanship, tight clearances and "spin tested" before being shipped. We asked about the pick up tube and o ring, they admitted didnt change it, we said it's gotta be that, they r&r'd it and sure enough it was crusty like a cheerio.

You could run a 10w30 oil with lucas and it would be just fine, no harm in using that weight oil even though the oil cap says 5w30 and thats what recommended.. 10w40 would even be fine.. which I say would be equal to running w30 with lucas. Or stick the 5w30 with lucas like I did and it's working for me.

Well I'll leave it at that for now considering it's a long write up I just whipped up at 1:30am.. looking forward to being part of the forum from this point on..

Let me know what you think!

well, no difference in idle oil pressure. once hot its still around 10 ish. higher oil pressure when driving though! actually stalled when I pulled into the driveway, then didnt want to start (took 3 trys to get it to start again).

 

[carrmann]

got the oil pickup tube oring changed. inspected inside the pan, nothing of note just some sludge etc. it seems to have improved driving pressure at temp, and slightly improved idle oil pressure. instead of 8-10 psi when hot in gear and idling, its at about 14-15psi hot/in gear/idling (about 550 rpm both times). fresh ac delco oil filter, fresh 6 qts 5w30 synthetic put in.

i have about 40 psi now at 1100 rpm roughly with the engine hot.
oil pressure switch/dirty screen in switch? any other suggestions? intake manifold orings? I know 15 ish is better than sub 10, but would like it to be 'correct' so I dont have to worry about the engine hurting itself.

Thanks!