https://blazerforum.com/forum/ Discuss 2nd generation S-series (1995-2005) general tech topics here. en Fri, 05 Jun 2026 00:50:40 GMT vBulletin 60 https://blazerforum.com/forum/images/kirsch/misc/rss.jpg https://blazerforum.com/forum/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/02-2wd-blazer-persistent-misfire-looking-fresh-ideas-107736/ Thu, 04 Jun 2026 00:07:17 GMT I've been chasing a sneaky misfire issue and wanted to get some opinions before I start tearing deeper into the engine.
~150k miles
Rough idle
P0300
Cylinder 3 misfire on scan data at idle, sometimes clears up around 1600 RPM

The current parts cannon list:
New fuel filter
MAF cleaned
New Ac Delco plugs and wires
New Delphi fuel pump
New Delphi distributor (retard at 2)
New Standard MFI spider
Cleaned throttle body
New EVAP components

Compression tested relevant cylinders before injectors Cylinder 3: 160 psi
Cylinder 1: 155 psi
Cylinder 4: 150 psi
Compression appears healthy on the missing cylinders

Still sets P0300
Misfire data is almost exclusively on cylinder 3 at idle
Around 1600 RPM the misfire almost completely disappears
Above ~2000 RPM the misfire returns
During a road test the engine began slightly missing on more than just cylinder 3, but i couldn't pin it as I was driving. I can hear a hissing sound on the passenger side of the engine bay but have not located it yet, sprayed some brake clean around the vacuum ports and intank plenum but nothing is increasing idle.
While driving, the brake pedal becomes super stiff as, if vacuum assist was lost.Once parked, the brake pedal feels normal again
STFT for both banks are around 0-3, LTFT are around -9 which throws me away from vacuum issues or single cylinder problems.
O2 sensors are sweeping in the graph, exhaust leak post cat due to terrible install, 02 spacer on that sensor

Any ideas are appreciated and im not afraid of diagnosis but this one has me stumped. Maybe crank sensor? It is covered in oil but giving me no reasons to replace. I'm trying to avoid throwing more parts at it and would like to get pointed toward the next logical test.
]]> 2nd Generation S-series (1995-2005) Tech Jacoby -_- https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/02-2wd-blazer-persistent-misfire-looking-fresh-ideas-107736/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/2000-trailblazer-battery-parasitic-draw-107731/ Tue, 26 May 2026 23:40:15 GMT Will a bad transmission transfer case vacuum switch cause a battery parasitic draw ?? also no 4 wheel drive. Plan on changing it & all Vacuum hoses. But curious about battery draw from actuator switch?? ]]> 2nd Generation S-series (1995-2005) Tech toys https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/2000-trailblazer-battery-parasitic-draw-107731/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/vacum-hose-size-4x4-drive-107727/ Thu, 21 May 2026 14:45:26 GMT I'm In Conn, my Blazer is in NY. Before I go NY Can anyone tell the Vacuum hose sizes I Might need to fix most under hood & 4x4 issues.(Damn the chipmunks) I'm taking a new actuator & transfer case vacuum switch with me. Is silicone better than rubber??? ]]> 2nd Generation S-series (1995-2005) Tech toys https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/vacum-hose-size-4x4-drive-107727/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/front-door-hinge-drilling-templates-107724/ Wed, 20 May 2026 16:53:48 GMT I would have no problem trying my loosey-goosey welding skills on refilling the egg-shaped hinge pin holes for the front doors, and then drilling out fresh ones. The biggest problem I see with it is... I would have no problem trying my loosey-goosey welding skills on refilling the egg-shaped hinge pin holes for the front doors, and then drilling out fresh ones. The biggest problem I see with it is trying to determine where the original hole centers were (and new ones should be). Won't help to have new perfectly sized holes if they're a 1/16" off in different direction. I've searched off and on for months to see if there's some kind of printable template I could lay on top of the hinges to mark the new hole centers, but can't find anything.

Does anyone know how everyone else does it? Have you done it? Any tips or advice would be welcome.
]]> 2nd Generation S-series (1995-2005) Tech allangee https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/front-door-hinge-drilling-templates-107724/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/when-move-if-ever-107719/ Sun, 17 May 2026 15:27:41 GMT 2004 blazer (4.3L V6 Vortec) 180k mi. How do I know when to move on from this vehicle, if ever? I have tried to exercise a high level of care for this vehicle, always changing the oil on time,... 2004 blazer (4.3L V6 Vortec) 180k mi.

How do I know when to move on from this vehicle, if ever? I have tried to exercise a high level of care for this vehicle, always changing the oil on time, trying to use good parts, etc.

I don't like spending money on cars, and if I have to spend then I want a reliable vehicle. I can do very minor repairs myself, but stuff like control arm replacement or intake manifold gasket are beyond my ability.

I don't want to overreact to the need for some repairs.

The vehicle has a very slight rust patina on the bottom but it is not rusted by any sensible use of the term. It has never been driven on salted roads. As far as I can tell the engine and transmission are in good shape. There is no blue smoke from the tailpipe. I have used this vehicle very gently and lightly--never towed, never off-roaded, and have carried a bunch of stuff in the back only on a few occasions. I don't push, redline, or even make demands of the engine, most of the time it just goes for either a stroll or a very long stroll.

I am facing:

(a) Control arm replacement (probably only one lower is necessary but need to do this symmetrically and then it is only a moderate additional cost to also do the upper control arms, and I can't make a ball joint-only or bushing-only replacement cost effective). Sourcing parts has been hell -- if someone knows how to source OEM GM control arms please let me know. I am having great difficulty making judgments about aftermarket parts, not uncommonly they cut corners like not having zerk fittings which I find concerning. I am reading conflicting reports on the quality of aftermarket parts and it is rather distressing. This repair is above what I can do myself. I can only find Moog RK and I can't find Mevotech TTX for the replacement control arms. I have found AC Delco lower control arms but I'm slightly worried about the quality of AC Delco.

(a.1) The sway bar linkage has rubbery components which have some significant cracks and these will probably need to be replaced.

(b) A weeping intake manifold gasket (not urgent, but this will need to get fixed in the next few years). If I understand correctly, a steel core Felpro is the way to go here, and I am not too worried about that component.

(c) Oxygen sensor replacement (not a big deal, I can do this myself). This alone isn't much of an issue but I am thinking that other parts may start to need replacement.

(d) Horn sometimes doesn't work. Something about pressing it in seems to fix it but then it stops working again.

(e) The instrument cluster blinked off for a long while. Somehow it started working again--I think going over a bump (??).

(f) The windshield wipers sometimes remain stuck on and I have to fiddle with things. This is not yet properly fully broken, but unfortunately I think I need to say that windshield wipers are a necessity and I imagine that I will need.

(g) Undiagnosed oil leak -- an oil pan which is wet everywhere with oil. This isn't such a bad leak that it is dripping. I am not totally sure what the problem is, maybe a busted oil pan gasket? Or could it be a rear master

(h) An AC which does not work, probably a minor leak somewhere.

(i) The center console gets rather hot near the HVAC controls--maybe a heater core issue (?) I am not sure of this one. I am tempted to say also that the cabin is constantly being heated.

(j) I don't want to demand luxury but there is no air recirculation, no cabin air filter, and air from the outside enters the cabin not instantly but it does get in quickly. I tried to investigate the seals but this seems difficult and costly to sort out. I considered renting a fog machine and putting it in the cabin to see where smoke comes out.

I have already done these repairs:

1. Oil coolant line replacement. It was extremely difficult to source the OEM GM part for this, but I was successful.

2. Automatic transmission pan gasket. When this was replaced there were very few shavings in the transmission pan and the mechanic said that the transmission is in good shape.

3. Fuel pump (replaced twice). The first fuel pump replacement failed because the mechanic used a low quality part against my wishes. I wasn't able to source the OEM GM part for this repair despite my best efforts, I am crossing my fingers that Napa auto is correct that the Delphi fuel pump I chose is equivalent to OEM.

4. Idler arm replacement.

5. Rear rotors, rear brake calipers. The brake calipers had to be aftermarket remanufactured. This wasn't too big of a deal.

I don't like nearly all newer vehicles.

I would only drive a naturally aspirated or electric vehicle, or possibly a toyota hybrid. There are very few V6 vehicles which can be purchased, and the ones which can be purchased are extremely expensive. Quite often there are turbochargers which shred the oil, and the cylinder count has been pushed down which pushes engine wear and temperatures up. I hate to seek luxury but 4cyl vibration is no fun. I am terrified of repairs of newer vehicles. I looked at the Chevy Trax but 3 cyl turbocharged with a wet belt seems like a vehicle which needs to be sold within 50k mi.

I am also faced with the fuel costs of this vehicle, which I have measured at 12mpg in city-intensive driving and 19mpg for highway-intensive driving.

I am not sure what other repairs are coming down the line for this vehicle. ]]> 2nd Generation S-series (1995-2005) Tech black04blazer https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/when-move-if-ever-107719/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/died-pulling-away-after-putting-few-gallons-now-crank-no-start-107718/ Sat, 16 May 2026 06:52:29 GMT Anyone want a blazer? Bout to sell this roaming headache
Wouldn't start after initial death, started once and made it a block down the road and died again and just crank no start
]]> 2nd Generation S-series (1995-2005) Tech BlazerNovice92 https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/died-pulling-away-after-putting-few-gallons-now-crank-no-start-107718/ https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/dorman-control-arms-107717/ Fri, 15 May 2026 00:30:08 GMT My 2004 blazer 175000 mi needs new control arm bushings. I am having difficulty sourcing OEM GM control arms. Are dorman control arms going to also last 150k+ mi or are they not so good (10k to 50k... My 2004 blazer 175000 mi needs new control arm bushings. I am having difficulty sourcing OEM GM control arms. Are dorman control arms going to also last 150k+ mi or are they not so good (10k to 50k mi lifetime) ?

Or is there another brand I should use? ]]> 2nd Generation S-series (1995-2005) Tech black04blazer https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/dorman-control-arms-107717/