Chevrolet Trailblazer Valve Job Part 1; Teardown 

Just wanted to say thank you for these 2 videos,,, I used them to guide me along after the my trilblazer valves went bad. Sure helped to see what I was getting myself into.

Thank you SO much for posting these videos. Very impressive work. Not sure I will be taking this on myself.

Yours is the only video I found, thanks for posting it. So glad I didnt start this, more than I want to take on. Taking it the garage.

Your video was well done. You have the patience of Jobe. Thank u for sharing and I see in comments you have been very supportive to others.

Very good job. I like your approach with the chain problem.

Thanks for making and sharing this video! The timing chain trick with the wire will be useful.

Wow that is a brave undertaking from where i am sitting. Good luck w the repair!

Great video!!! Thanks. Just did mine (2004 67K miles - burned exhaust valves #3 cylinder, low compression). Actually had to do the job twice! because Autozone sold me a reman (American Cylinder Head) that had a cracked water jacket, so coolant leak when put back together. Used your "turnbuckle" system which worked great! Also bought the special tools to hold the timing chain but with the wire/turnbuckles they aren't totally necessary. Second time I did the job I machined the "special wedge tool" on my CNC that goes down into the timing chain cover and secures the chain from falling down off the crankshaft sprocket. It also makes the whole pain of releasing the timing chain tensioner and retracting it unnecessary. You can just pop the timing sprockets back on. I also bought an 8mm 1/2 inch drive allen socket and cut it down just short enough to go into the new exhaust timing gear bolt, and used with a "bolt stretch" torque wrench you don't have to pull the radiator shroud off (like another 2hrs of work). I used the "pound on the headbolt" technique and only broke 3 headbolts....2 were the very rear where you can't really pound them. Amazon sells a great kit for extracting them similar to the GM tool but MUCH cheaper. smile.amazon.com/gp/product/B006YDQ812/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 Thank you again for the video, it was really helpful!

Very well made video, also I would like to add this is pretty much the same way to take apart the i5 on a Chevy Colorado & GMC Canyon.

Good work, nice and detailed to the point.

I disconnected the battery let it set for 20 minutes reconnected the battery and turn the key on and waited a couple minutes before I turn the key to the start position the truck seems to hang up on something until you bump it two or three times then it finally turned over and runs it's very rough I can not even go down the street in it now it is overheating instantly you are the coach from today

Awesome job, nice and clean

Thank for this video great job

Thanks for this video, I have one of these trucks and I want to keep it going as long as I can, I'll probably scrap it when it gets into a giant wreck

you did a great job!good video I'm doing same thing on 04 envoy

Mi pregunta es en que momento quitastes los tornillos de caveza si siempre se capan

I can't say thank you enough for your help My trailblazer will sit there and idol up to three hours at about 160° maybe 180 AC or heat on but the minute you drive it it starts to heat up I thought this might help you some hope to hear from you soon

I have a 2007 TB with just over 100,000 miles. Was getting a P0305 cylinder number 5 misfire code constantly. I changed the plugs (with AC Delco) and swapped coils from another cylinder and still got the misfire code for cylinder 5. I finally did a cylinder leak down and a compression test on all 6 cylinders. Cylinder1: Leakage: 20%, could feel air leaking through throttle body, Compression check: 210 PSI, Cylinder2: Leakage: 9%, could not feel any leakage, Compression check: 220 PSI, Cylinder3: Leakage: 22%, could feel air leaking through throttle body, Compression check: 215, Cylinder4: Leakage: 11%, could not feel any leakage, Compression check: 220 PSI, Cylinder5: Leakage: 69%, I did a smoke test and could not only see smoke coming out the tail pipe but could also hear the air hissing into the exhaust. Compression check: 160 PSI, Cylinder6: Leakage: 7%, could not feel any leakage, Compression check: 220 PSI. Looks like I'm pulling the head.

I have 347000 miles on mine still runs good. 2006. 4.2

Thanks for posting this. I just finished getting my head out and my problem IS burn exhaust valve. Unfortunately, I broke 8 or 9 head bolts, but I didn't freak out because everywhere I read it said to expect that. I tried shocking the bolts and I didn't jerk the wrench to loosen them. It just seems unavoidable. Also, in my Chilton book and on this video, I didn't see that you have to unbolt the Timing chain guides before you try to take the head off. I wound up braking one of mine so I'll have to take the front cover off to replace. Not a huge deal, it's only $23. There's also a piece mounted to the back of the head that is a sort of pass through for 2 (what look a cooling and a vent hose). That wound up breaking also when I was trying to get the head out. It's very fragile. So I'll have to get on of those too.. Thanks again.

Well done video. i have an 03 with 260k on the motor. no major issues but i was considering tearing it apart in the summer and replace all seals and clean up carbon.

i cant seem to get the intake manifold out and im positive i have undone all of the bolts. is there something im missing?

the coolant was chevy and distilled water...there were some codes .ill look for them..the dash cluster stopped working and while i had it out ,i found the engine lite had been taped over .when i put the cluster back in engine light was still on ,,maybe 6 months later all this started . should i have it scanned now ?

did you get the post cylinder compression today ??????

First I want to say great video, very informative! My truck started idling rough after a quick trip one night and had to drop it in neutral to keep it from stalling out at stop signs. After running a bunch of tests, your video helped me figure out what could be wrong. Now for my question. I have disassembled my engine to facilitate removal of the head but I have a concern with the timing chain. All of the literature I have seen shows the cam timing marks lining up with the dark links of the timing chain. Mine don't. They're not even close, the dark links are 3 links advanced at TDC. Is this cause for concern? I need to pull the head to get it machined but this has me stopped dead in my tracks. Am I being overly cautious?

How did you removed the throttle body? Like that black piece, can't take it out

i just pulled the plugs getting ready to do a leak down test,,i found little specs of water on 3rd cylinder back from the front of motor ,,,should i continue with leak down test ????

pfun41 i decided to change my spark plugs on my trailblazer 03 LS 4.2 and found out that two sparks has oil not to much but yes was some oil in there my question is should i need a new valve cover gasket or do i need something else such intake manifold gasket ?? I hope you could help me thanks in advance brother .

If this is a common problem then I'm gonna run MMO in the engine. apparently MMO can clog up the VVT though. Any advice? Just synthetic oil then?

You did a great video. The locks on the electrical plugs; the removal of the broken bolts would of helped I think. Not everyone is as experienced as you. Using bungee cords (heavy rubber type works well for holding the timing chain also. You helped me to get the exhaust cam actuator back on. Thanks. It had me stymied. Also the three small bolts at the front need to be degree tightened also. I broke one off tightening it. Made a guide and extended drill bit and got it out. Whew!!!! Thanks again!

HOW CAN I CONTACT YOU ? I need my truck fixed

how many bolts needs to be removed

Hey man not sure if youll reply to this, but ill give it a shot. When you started pulling the head, you removed the wires from the side, then added wires to the top of the chain to keep tension, correct? Then when you had enough clearance, you re-tied the side wires right? Thanks

Having problem with leaking valve cover gasket on 08 envoy 4.2 a more detailed description would be helpful on replacing it.

Good for you and nice job I love it this my job to good luck 🔧🔧🔧🛠️🔨🏅

how do you get that intake out

Can some one tell me where the oil pressure switch is located.

WHEN THE OVER HEATING STARTED I ALSO LOST MY CRUISE CONTROL....JOHN

nice

Thank you for taking time to make this video, I am about to remove the valve cover to replace the gasket and would like to ask if you removed the coolant from the vehicle before you started filming or I can get away by just removing the bolt holding the houses and just moving them to the side long enough to get the valve cover off.

I wish I knew how to tore apart that big black plastic thing where the throttle body seats that covers the injectors rail.

How did you get out the last bolt on the intake manifold (closest to the firewall) off?

On your video you take the intake & throttle body off. My question is how do you get to the last bolt by the firewall. What wrench, socket, etc. did you use. What is the tip/trick to getting that one out.

I have had heat problems with the middle valves on 4.3 's. I am thinking it's because, being in the middle less air circulates & it cannot cool itself as well as it should or needs to. I'm going to try and improvise some sort of air damn to move more air around it Thanks for the vid.

when separating the block from engine did u have to release the tension from the chain? it seems like that part got skipped in the video

no i have not ,when it idles you can hear something going on/off.the old fan you could stop with your hand.i am down to the intake manifold. should i stop and look at the relay.by the way the compression is great no water in oil .,passes the block test,and pressure test..thanx so much john

i don't have a way of clearing codes.it wasnt bad.a little grimy but nothing missing...should i try a leakdown test 0n # 4 cylnder ?????

I got the exhaust cam actuator in and I got crank shaft sensor on the front of the engine installed Do I need to unhook the battery reset any fuses or anything like that

Any tips on getting all of these broken Head Bolts out? (Broke all 14!)

How many head bolts broke

What's connected to the back of the head? How do I remove it? That's all I have left to get the head off. Only broke 2.9 head bolts in the process lol. One still has both pieces connected by .080 worth of a single thread. I was amazed. But back to the question. What is it and how do I disconnect it from the back of the head? Thanks.

hey i just got these codes read and hour ago ,,,,C0055 abs....C0201..P0113..P0141... P0300...P0014....I JUST RENTED BLOCK TESTER,,COMPRESSION GAUGE....PRESSURE TESTER FOR RADIATOR....THANKS AGAIN ,HOPE TO HEAR FROM YOU SOON..JOHN

I took out the one were the alternator was but the one behind the tube I must of missed do I have to fully take of the tube to get to it

I have a '05 TB with around 98k miles, my question is: Is there any kind of preventative maintenance I can do in attempt to avoid this problem? or is this issue just sort of a 50/50 chance? I'm not experiencing any problems infact she idles and drives just fine, I was just not aware of this valve problem until I came across this video.

IM DOING A ENGINE SWAP on a 2004 trailblazer 2wd 4.2 in line 6 . when i try to put motor and tranz together the converter will not spin free.. apart the converter spins free.when i mount the converter in tranz i have waited till i feel the two clunks..please help

I got the actuator in and the cam sensor right at the front top of the motor it's running worse than ever and heating up twice as fast any suggestions

Great job BTW, I think you have the only video on youtube doing this Engine! 4.2L I6 goes in all Trailblazers/Envoys from 2002 to 2009. And it's not a easy job by no means. What would be a decent cost to have this done on a 2004 TB? I just changed my Air Filter, gas filter, Cleaned the Throttle body. I have NO engine light on & in cylinder 3 & 4 the spark plugs had oil on them. This TB never miss fired yet. What would you do? I thought I'd just drive it until I get a light of some kind & then cheek out the problem. Help please?

If I have to pull this transmission back out is there anyway that it can be done leaving the motor in the truck

Is it very important to fix this problem? What could go wrong if I just leave it be?

will you let me know where are the bolts for the parts you are pulling out, the video is so fast I need to get to the valve cover bolts, for your helpp thank you.

Would a bent push rod or broken valve spring cause a cylinder to misfire

What did it end up taking to get the broken head bolts out?

how did you get the intake off I'm having a hard time trying to get it off please help

I put a new bottom radiator hose on and New fan relay it's back to doing the same old thing Dryvit 10 minutes and it overheats and just pegs and it's missing worse than ever any suggestions I would appreciate it

Im doing the same job right now. I've remove all the head bolts but the head still doesn't want to break loose. Is there something that i'm missing? (only had 5 head bolts that didn't break).

how many total bolts are on the black piece,... after the mount and alt are taken off, the video skips to removing it.. Just trying to understand.. thanks

What is the torque number on to 10mm bolts holding onto the valve cover (5:27)? Would it be the same on 2003 Oldsmobile Bravada 2wd?

I'm talking about the actuator that goes into the passenger side engine block right at the top and the crankshaft sensor that you right in front of where you put oil in the motor at this is a 4.26 cylinder

I just finished my engine swap on the 2004 trailblazer my transmission will not engage is there any sort of procedure like bleeding or anything that I should unplug and plug back in or any procedure that I should check out I jack the car up and I had nothing now he goes up to about 10 miles an hour and then it just stops working again

I have a 02 Chevrolet Trailblazer and I replaced the water pump joint with the housing brand new and it still overheats, what can be the problem

I got it out, but now I have a message that says 'reduced engine power'. do you know anything about that?

should i put it back together and investigate the fan relay

what bolt do you need to remove to get manifold lose?

Thanks for the information. I got 10 bolts lose, but now the problem I'm having is that the manifold is not coming out, it's lose but won't come out.

So doing it this way, you can leave the AC compressor? Don't have to recover freon? Also, anything you would do different if you did this again? I will be doing this soon on my girlfriend's 05. It overheated and the water pump blew. Replaced the water pump, but there's oil in the coolant. There's also been oil building up in the #3 cylinder for a while, so I think it's time to machine the head and replace the head gasket.

I noticed you completely skipped over taking the intake off 😂 that last bolt will have you editing the WHOLE session out of the video

This engine looks alot like the 3.5 i5 vortex in the H3, would the processes be very similar?

Please help,,,, how many bolts are there to get manifold out????????????? Ben working on truck for 8 hours and I'm tired but not willing to pay mechanic $400

When removing any Gm atlas head bolts just use a hex socket with a ratchet or breaker bar and hit the top of bolt/ratchet while loosing the bolts. Go slow most or all will come out.

what is the tool used to get head bolts off?

i cant seem to find the correct video

Great video!! Could I ask anyone here at around what mileage Trailblazers start to have this particular problem? Mine is an '05, has 140K on it. Just wonderin' about when this will happen if you can give me a ballpark. Thanks!!

As fast as we live I don't know who can still do that if your job it's completely different than a mechanic. If I can get to that point on removing all that, maybe I won't put it back and I will toss the tools away. And call the scrap truck

i meant to say on the plug [specs of water] at the 3rd cylinder

Mine just started doing a lot of tapping and a little belt squeal. Popped the hood and saw oil down the driver side, all the pulleys and noticeable power loss. Just hit 170k in the old girl. I knew she was about to shit the bed soon and boooooy in the middle of a road trip she did. I knew it was gonna be a valve. I don’t want to 😩😩😩

OK I WILL TRY THAT

the tranz is dry could that be part of my problem ?

ok so where's the exhaust cam actuator at.... just to be sure

cant seem to find the proper timing marks for #1 cylinder at tdc

is it hard to change the head gasket

As a vehicle gets older,I factor in resale value to repairs. If the cost of repairing an engine costs more than the resale value. I sell the vehicle running as is for whatever I can get for it. If I deem the vehicle cost prohibitive,I scrap the damn thing. I think pulling that motor would be time consuming and really not worth the effort. Someone willing to repair that for a reasonable price would be almost a joke. Sadly mu 03 Trailblazer is almost at the end of its useful life. I have no problem selling it as a drivable parts vehicle,as is. At 200k plus miles,we got our moneys worth from ours.

137k new radiator .hoses ,thermostat .water pump ,,new plugs ,,map sensor.,,,will only cool down when you turn the heat on,,,that only last about a mile,,, the truck runs great after 2500 rpm

auto zone said there's wouldn't clear codes...to be exact what do you mean get the VVT problem taken care of.

HOW MUCH WAS THE HEAD WORK JL

how many miles on this motor

so the alternator has to come off in order to get to the bolt

Guy looks like the giant from the movie big fish but with red hair

Lets see I've replaced the fan clutch, soldered new instrument clusters then bought a new instrument panel now some of those are going bad, couple of speakers have blown, 3rd cylinder was leaking and was quoted an estimate of 2500-4000 from chevy dealership where vehicle was purchased but i got lucky with a totaled gmc with 80k on the 4.2l replaced with that and paid 400 for engine and 50k miles later 3rd cylinder came back to bite, a/c broke. If this isn't just a simple coil fix for 3rd cylinder I'm done wasting money, I love my car but I've got to find something else...good luck to anyone else who dares so this job or pull the motor it was a pain in my ass then and I'm not going through the same nightmare twice.

Hey man I have a gmc envoy 4.2 same truck I can not get the intake manifold out please help I have everything out the alto atop throttle body anything to possibly block it just seems to be like stuck in place Please help asap thank you gladly appreciated

wow i can get a motor with 82k for $900.my problems are over heating and missing.when i saw your video it sounded just like my problems. it has new radiator,thermostat.fan shroud,new fan clutch,,when i put the new radiator it ran good for two months.and now you can only go 5 minutes then it starts boiling over.if you turn the heat on it goes down for about 5 minutes then it sounds like the radiator is about to explode..i tried taking out thermostat it made things worse