02 I6 no start help

[danger]

OK let me preface this. New to the forum, and I need some advice or help. I recently bought a 02 trailbalzer for cheap. Check engine light was on, and running rough. ran a scan and it was throwing a p0340 code. I changed the cam positioning sensor, and cleared the PCM. Doing this helped the vehicle to run smoother, but was still acting like it was misfiring. Check engine light came back on, and I put the tester to it again thinking it would give me a p300 code. instead it gave me a p0014 code (positioning actuator solenoid). After some research I went to get my oil changed and took it out to run it out. It ran the same and was still feeling like a cylinder was misfiring at idle. I was stopped at a stop sign and went to accelerate and then all of the sudden I heard a "pop" and the engine died. Luckily my son was right in front of me and turned around to see what happened. He towed me back to his place and I started trying to trouble shoot the problem. I replaced the positioning solenoid, and attempted to crank it. it tried to crank but backfired through the intake.... my initial thoughts are it jumped timing. this brings me to my question...has anyone else had this issue and what was the problem, and 2 how would I go about checking if it jumped timing?

 

[The_Roadie]

Welcome! With the robust timing chain we have, the tensioner would have to be very, very borked to allow jumping. Don't think I've ever read of that happening. There are manuals available to download here in a sticky thread. Or you might buy the Haynes or Help GM OEM manual if you want to dig into it that deeply.

Obligatory questions we HAVE to ask to get up to speed: How many miles, any other maintenance history, has the throttle body ever been cleaned, and are the plugs and all fluids up to date?

 

[danger]

Welcome! With the robust timing chain we have, the tensioner would have to be very, very borked to allow jumping. Don't think I've ever read of that happening. There are manuals available to download here in a sticky thread. Or you might buy the Haynes or Help GM OEM manual if you want to dig into it that deeply.

Obligatory questions we HAVE to ask to get up to speed: How many miles, any other maintenance history, has the throttle body ever been cleaned, and are the plugs and all fluids up to date?

it has 217K miles on it and since I just bought it I would have to assume the throttle body has never been cleaned. Fluids were just brought up to date 2 hours before this happened. Plugs... again.. I have no clue when they were last changed.

 

[Texan]

Here is a link about the PO014 code. Starting point.
Read through it, and ask questions as necessary.

http://gmtnation.com/f93/how-clean-...osition-actuator-solenoid-picture-heavy-2263/

 

[danger]

Here is a link about the PO014 code. Starting point.
Read through it, and ask questions as necessary.

http://gmtnation.com/f93/how-clean-...osition-actuator-solenoid-picture-heavy-2263/

No need to clean... I replaced it.... as stated above....

 

[Texan]

Sorry I missed that point, but I would check the easy things first. Plugs, fuel pressure, ect.
I agree with The_Roadie that the timing chain system is robust. If you dig through some of
the threads, you will find some information about the system. You asked about how to check if
it jumped time. This is not a easy task. It requires removal of the valve cover and intake manifold
and front cover. I would look elsewhere where first.

 

[IllogicTC]

Welcome! With the robust timing chain we have, the tensioner would have to be very, very borked to allow jumping. Don't think I've ever read of that happening. There are manuals available to download here in a sticky thread. Or you might buy the Haynes or Help GM OEM manual if you want to dig into it that deeply.

I have.

I had the same problem. I took it to the dealer 4 times and they changed all the sensors but the problem stayed the same.I was then told I had a bad crank shaft and would have to replace the engine. I refused to believe the engine was bad at 80,000 miles so I got a second opinion from an independent mechanic. Turns out the hydrolic tension pully on the timing chain was stuck, chain was loose and it jumped time. He replaced the pully and the chain and now Ihave 189,000 miles and never had the problem again.

- from a thread on Topix, Googled for "trailblazer timing jump." All spelling errors are sic, I just copy-pasted it. I mean what are the chances, sure, but it's not ENTIRELY out of the question. The thread was about the P1345 code, by the way.

And danger - it's good to see you made it over! We'll try to make sure we take good care of ya, my alter ego Gnat's clues must be working!

And if it comes down to "it's probably jumped timing" as you suspect, if you get the manuals as The Roadie suggested (in a sticky thread called Service Manuals? Get them here! in the Technical Discussion area), the file 4.2 Engine Repair page 44 shows how the chain and all that should line up.

There's a lot of crap to remove to get the front cover off, so you could go with a preliminary check by removing the valve cover and checking the two sprockets up top, if one of them shows it's off then there'd be the rest of the digging and removal to do. With Cylinder 1 at TDC, both sprockets up top (one for each cam) has a dot on the front of them that should line up with a darkened link, it's noticeably darker than the others (engine varnish may make it hard to see if it's too bad). Each dot should have a darkened link on it. If not, then it's indeed jumped.

 

[gmcman]

If the TB looks as dirty as you stated, I would get a can of BG44K and a new fuel filter and run that tank first before you throw any money at it. You could very well have a lot of carbon built up under the valve seats.

I would do this before anything and I would do it tomorrow.

 

[danger]

I have.

- from a thread on Topix, Googled for "trailblazer timing jump." All spelling errors are sic, I just copy-pasted it. I mean what are the chances, sure, but it's not ENTIRELY out of the question. The thread was about the P1345 code, by the way.

And danger - it's good to see you made it over! We'll try to make sure we take good care of ya, my alter ego Gnat's clues must be working!

And if it comes down to "it's probably jumped timing" as you suspect, if you get the manuals as The Roadie suggested (in a sticky thread called Service Manuals? Get them here! in the Technical Discussion area), the file 4.2 Engine Repair page 44 shows how the chain and all that should line up.

There's a lot of crap to remove to get the front cover off, so you could go with a preliminary check by removing the valve cover and checking the two sprockets up top, if one of them shows it's off then there'd be the rest of the digging and removal to do. With Cylinder 1 at TDC, both sprockets up top (one for each cam) has a dot on the front of them that should line up with a darkened link, it's noticeably darker than the others (engine varnish may make it hard to see if it's too bad). Each dot should have a darkened link on it. If not, then it's indeed jumped.

Yes' Ill I made it over.I also saw May06LT's videos and that helped.I downloaded and reviewed the service manuals earlier today. I was just hoping someone might know of a way easier than having to crack the valve cover cover off. I also recorded a bad video so you guys could hear it.
02i6danger - YouTube
I can work on vehicles but it is really something I do as a last result.... but it looks like I might have to get use to doing it again.

 

[triz]

It sounds like rod knock when you try to start it. The quick video made me suspect it's off timing. It was too short to be certain though.

 

[danger]

It sounds like rod knock when you try to start it. The quick video made me suspect it's off timing. It was too short to be certain though.

the problem is. it won't run. when you force it... it backfires through the intake. which also leads me to believe it has jumped timing. I don;t want to do too much more and risk bending the valves....

 

[danger]

Well guys here is the update thus far... 1 you guys were right.... just even checking to see if it is in time is a project. I have everything off right now except the intake manifold and what I have found thus far is that the (autolite) spark plugs were crap. I don't even know how #1 was even firing. the coil packs seem to be in good shape however they do need a cleaning. the throttle body will get a through cleaning. The #1 spark plug hole was full of oil and I mean full. The seal around the top was not properly seated. In a way I am glad this happened, because I will know this engine inside and out by the time I am done.

 

[jsheahawk]

I also recorded a bad video so you guys could hear it.
02i6danger - YouTube

She sounded pleased.

Well guys here is the update thus far... 1 you guys were right.... just even checking to see if it is in time is a project. I have everything off right now except the intake manifold and what I have found thus far is that the (autolite) spark plugs were crap. I don't even know how #1 was even firing. the coil packs seem to be in good shape however they do need a cleaning. the throttle body will get a through cleaning. The #1 spark plug hole was full of oil and I mean full. The seal around the top was not properly seated. In a way I am glad this happened, because I will know this engine inside and out by the time I am done.

You will probably solve the oil issue with the new gasket you'll be putting on. So that's a plus!

I'm on the edge of my seat waiting to find out if the timing chain jumped.

Jared

 

[IllogicTC]

the (autolite) spark plugs were crap

You are already contributing to our knowledge database by reaffirming something we all like to tell each other

It's interesting that people will try selling Autolites went they don't even make ones for the TB. The Walmart manual on spark plugs shows all the brands of plug and whatnot, and Autolite does not have one listed (Bosch has a couple though). However we all still recommend going OEM with replacement plugs, for the I6 you would want ACDelco 41-103. They are iridium (they've superseded the platinum plugs the TB originally came with) so gapping is not recommended (it IS possible, done very carefully, using a pair of pliers on the ground strap) and one of those round spark plug gap checkers is the kind NOT to use to check the gap. They should come pre-gapped, by the way.

 

[danger]

You are already contributing to our knowledge database by reaffirming something we all like to tell each other

It's interesting that people will try selling Autolites went they don't even make ones for the TB. The Walmart manual on spark plugs shows all the brands of plug and whatnot, and Autolite does not have one listed (Bosch has a couple though). However we all still recommend going OEM with replacement plugs, for the I6 you would want ACDelco 41-103. They are iridium (they've superseded the platinum plugs the TB originally came with) so gapping is not recommended (it IS possible, done very carefully, using a pair of pliers on the ground strap) and one of those round spark plug gap checkers is the kind NOT to use to check the gap. They should come pre-gapped, by the way.

I never use autolite or bosch.... the ONLY thing I have ever put in any of my GM products was AC Delco. This TB is just the recent addition to the herd. I also have a 96 GMC Seirra 7.4L EX Cab, and a 97 GMC Jimmy SLE which is also in project mode.... Right about now I am thinking I probably should have put the money into the jimmy to get it back on the road, but I have wanted a TB since they came out. I figured for 1800.00 in good condition, and 217K miles... I couldn't go wrong... after all... it was JUST a SEL on... how serious could that be

However... someone needs to tell me the magic trick to getting this intake off... it has been a serious pain....:banghead:

 

[MAY03LT]

If it jumped time I woulda expected to see a cam/crank correlation code.

It's hard to tell what's wrong when listening to a vid, but in the vid it sounds like something is broke up top. I don't know how deep you are in it right now but if you're not too far in it might be worth doing a compression test.

Also

May06LT

How dare you!

 

[triz]

If it jumped time I woulda expected to see a cam/crank correlation code.

It's hard to tell what's wrong when listening to a vid, but in the vid it sounds like something is broke up top. I don't know how deep you are in it right now but if you're not too far in it might be worth doing a compression test.

Also



How dare you!

He could not get it to stay on, so it won't toss one. I agree something sounds bad. It sounded like rod knock to me. But something could be broken. Possibly a timing chain guide perhaps if he's lucky.

 

[danger]

I'm 1 bolt from having the intake off, and then 10 minutes from having the valve cover off... that will happen this evening. I already have it set to TDC, so the minute I have the cover off. I'll know... to be honest. I hope it isnt something that serious. especially after watching the video's posted here of the head rebuild and all the trouble he went through to change the timing chain.

 

[gmcman]

Just a word of caution, when you have access to the timing chain...don't remove any bolts unless you know exactly what they hold together. A few have removed a bolt and landed the chain in the bottom of the cover...This will ruin a weekend.

 

[danger]

View attachment 34093
OK you guys tell me, but to my untrained eye... it doesn't appear to be out of time. However on the exhaust actuator. I don't find a timing dot.
an inspection of the block I don't find any oil leaks or any place where a rod could be thrown. Everything in the top half of the engine looks to be right.
I guess what I need to do next is compression test the cylinders.

 

[gmcman]

Have you rotated the gears?

 

[gmcman]

I was serious about the bg44k, with the intake off can u get a remote camera of some sort to view the top of the intake valves?

 

[IllogicTC]

View attachment 21735
OK you guys tell me, but to my untrained eye... it doesn't appear to be out of time. However on the exhaust actuator. I don't find a timing dot.
an inspection of the block I don't find any oil leaks or any place where a rod could be thrown. Everything in the top half of the engine looks to be right.
I guess what I need to do next is compression test the cylinders.

I can clearly see the intake dot, but like you said not the exhaust one. It may be on the bottom side of the sprocket but shouldn't be, as it appears to line up with the DELPHI markings that are at a slight cant just as the intake sprocket is. Any chance of clearing some of the varnish and seeing if maybe you can get a clearer picture of what's going on? I mean a picture in your head, but a picture for us is always nice, too.

 

[danger]

View attachment 34098
yes I have rotated the gears.... here's one for you guys... this appears to be a laser mark. it's directly under the black link so it IS in time....

 

[MAY03LT]

Here be the marks.

 

[danger]

Alright guys, since it's in time.... I'm really stumped at this point. I'll get a compression tester and test the cylinders. I can change the plugs, clean the throttle body, all the intake manifold bolts were tightened.... no oil leaking and no signs of a rod being thrown.... I'm clueless...

 

[danger]

Here be the marks.

I got that from the service manual, thanks May03. Any ideas as to what it could be?

 

[gmcman]

The only way you are going to get a "pop" through the intake is if the ignition timing is severly off or an intake valve is hanging open.
Check all the lash adjusters, make sure everything moves freely. I'll leave the BG alone after this but it's very fast and very effective. I'm not sure why you tore it down before trying it.

Rotate the engine over 3 times to ensure the marks are lined up.

Could very well be mechanical, could be dirty electrical.connections...electronics spray comes in handy.

I would get an air compressor fitting for the spark plugs and with the valves closed charge the cylinders and listen through the intake ports for leakage.

Do this before you put it back together.

 

[Texan]

I got that from the service manual, thanks May03. Any ideas as to what it could be?

The answer to your question may be up in #12. Autolite.

 

[gmcman]

The answer to your question may be up in #12. Autolite.

Danger, could you also let us know what the plug numbers of the Autolites are?

 

[danger]

The only way you are going to get a "pop" through the intake is if the ignition timing is severly off or an intake valve is hanging open.
Check all the lash adjusters, make sure everything moves freely. I'll leave the BG alone after this but it's very fast and very effective. I'm not sure why you tore it down before trying it.

Rotate the engine over 3 times to ensure the marks are lined up.

Could very well be mechanical, could be dirty electrical.connections...electronics spray comes in handy.

I would get an air compressor fitting for the spark plugs and with the valves closed charge the cylinders and listen through the intake ports for leakage.

Do this before you put it back together.

I tore it down because all the indicators were that it was a timing issue. IF it HAD jumped time... spinning it up you run the risk of bending the valves....As for the BG... doesn't the engine have to be able to run to use this? I have spun it about 5 times now and everything lines up and everything appears to be tight.

And yes I am starting to think the autolites did play a part....

 

[danger]

Danger, could you also let us know what the plug numbers of the Autolites are?

APP5263

 

[triz]

Did you inspect the timing chain guides for wear or breakage? While you have that off make a thorough inspection.

 

[danger]

APP5263

according to advance autoparts... this plug shouldn't have even been considered for the TB... but we knew that already....

 

[gmcman]

If it had jumped time it would be running goofy all the time and if the valves were going to be damaged it would have happened instantly.

I agree....I'm sure a fresh set of 41-103's will work wonders also.

 

[gmcman]

according to advance autoparts... this plug shouldn't have even been considered for the TB... but we knew that already....

I looked up those plugs, heat range is 3 and the delcos are 5. Not sure how much that plays a part but someone went cheap on the last plug change.

 

[danger]

with these autolites being installed in it... I wonder why it didn't throw a p0300 code?

 

[gmcman]

What do the plugs look like, pics?

 

[MAY03LT]

I got that from the service manual, thanks May03. Any ideas as to what it could be?

If it is definitely in time I'm going with gmcman on possible intake valve(s). You might be able to save yourself the hassle of buttoning it back up just to do the compression test by skipping it and doing a leakdown test on each cylinder.

And yes I am starting to think the autolites did play a part....

I've heard of them wiping out coils and throwing p0300s but not causing mechanical damage. Unless I'm misreading this post.

Did you inspect the timing chain guides for wear or breakage? While you have that off make a thorough inspection.

 

[triz]

I am also interested in the oil level. Just another simple thing to check.