[Joe Mama]

You should make your wife pull the engine for you.

[Joe Mama]

It seems that this would be an excellent opportunity to visit the local salvage yard to retrieve the necessary parts.

[Joe Mama]

You are absolutely right… the black spots are exactly what I need for tail lights… will dig more into this when ohio temps come up above freezing.

Thank you btw on the repinning & wire harness inspection advice… will definitely put your helpful tips into practice.

[Joe Mama]

Have a few trouble codes with this vehicle… although the engine seems to be running very smooth & nice:

So it appears that there is a timing issue of some sort… possible cam phaser malfunction I would guess… resulting in low idle rpm. MAF sesnsor and fuel gauge diag should be pretty straight forward.

Q: any techs here familiar with any known issues with chevy trailblazer timing that could point me in the right direction?

Thank you in advance.

Pun intended.

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[Joe Mama]

Here are two more methods I would recommend:

This is my favorite…

This is the oldest and most guaranteed to work method… this is a lot of work, takes many sharp drill bits and takes a long time and a lot of elbow grease & a lot of patience…

Removing broken bolts is a great skill to learn. The extractor is the first choice… but if that doesn’t work, either of these methods will get you the results you are looking for.

[Joe Mama]

You have a CEL; pull the codes and get back to us.

Other diagnostics will include observation of PID data via a scan tool: short & long term fuel trim, MAP/MAF, IAT, ECT and O2.

[Joe Mama]

Other possibilities:

ATF fluid was intentionally left low during routine maintenance (transmission flush perhaps) because it’s easier to leave it low & add later…. than to try to remove fluid from an overfilled transmission (which can be difficult & messy.)

ATF fluid level was not checked properly; therefore, possibly indicating higher than it actually was at the time of service (or in this case, indicating ‘low’ when it could be actually ok.)

Any leaks are so small they are hard to detect and/or only leak under temperature/pressure demand (outside of your garage)

You can rule a lot of these things out by filling your system and seeing if the fluid level ever goes back down.

Be advised: unlike any other automotive fluid, the transmission fluid level must be checked via a certain established procedure (listed in your owners manual.) Here is an example of how to properly check trans. fluid:

[Joe Mama]

One issue I may have (literally just found out) is that the bleeder valve on the Legend calipers is facing down toward the ground and not up toward the sky. I’m not sure if that will cause issues with bleeding the brakes or not. I can flip the calipers to the other side if that is the issue.

Based on Pascal’s law, you should be able to bleed your brakes upside down & sideways because hydraulic pressure is equal in all directions:
[i]
Pascal’s law or the principle of transmission of fluid-pressure (also Pascal’s Principle[1][2][3]) is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same[/i]

I also realized when I was bleeding them by myself. I left the master cylinder cap off, could that have any effect?

Only if you have exhausted the supply of brake fluid in the reservoir; otherwise, there is no issue here. (Be advised that brake fluid is “hygroscopic” meaning it will pull moisture from the air; therefore, isolate brake fluid from the atmosphere at the earliest convenience.)

I’m assuming there is still a lot of air in the lines.

Even if your brake lines contained 100% air this should all be depleted with just a few brake applications.

Anyway, when I pump the brake pedal with the engine off, I slowly build pressure. When I release the pedal it immediately loses pressure and I have to pump the brakes again. With the engine running I have no pedal pressure at all. I can pump the brakes all I want and there is never any pedal pressure.

Brake hydraulics are very straight forward. Your issue will fall into one of two categories:
[u]
Internal leak[/u]: Your master cylinder is bad out of the box.. which unfortunately can more common than you think. (yes, this has happened to me)

External leak: open bleeder valve, brake line connection, caliper piston, wheel cylinder can all be suspect. In any case, you would have seen brake fluid pee’ing all over the place by now.

This is all based on the assumption that the bleeding procedure has been performed correctly for your vehicle.

[Joe Mama]

Since transmission hydraulics operate in a closed system, once filled, the ATF level should never drop.

Therefore, the only indication of low ATF is an external leak.

[Joe Mama]

Here is one possibility:

You should also perform a fuel pressure test to identify possible fuel pump/fuel pressure regulator issues:

You should also perform a fuel flow test to identify possible fuel line restrictions:

Here is how to perform an injector balance test to identify bad or dirty injectors:

I have started with small changes such as fuel filters and fuel injector cleaning solutions.

Here is how to perform a professional injector cleaning; you will need to use “GM Top Engine Cleaner:”

Here is a cheap, easy, & non-professional method:

Using a scan tool, further diagnosis would include observation of relevant PID data: short & long-term fuel trims, MAP/MAF, IAT, ECT and O2.

I am operating under the assumption that there is no fuel contamination (have you pissed anyone off recently? Married? Ex-wife?)

Making a lot of short trips without allowing time for your engine to warm up will accelerate carbon build up in your engine.

Good luck on ye’ endeavors. Be sure to let us know how this turns out.

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• 2002ChevyTrailblazerDriveability.jpg

[Joe Mama]

I didn’t see any TSB’s for an automatic transmission (4R75W) for your vehicle.

You appear to be experiencing a problem shifting from direct drive (3rd Gear / unbanded) to overdrive (4th gear/ banded).

I wonder if you might be going down this road…..

[Joe Mama]

Well sir, I’m impressed.. awesome help for such an obscure failure… will definitely check this out.

[Joe Mama]

One possibility is a line restriction. Test suspect parts by blowing air through them.

[Joe Mama]

Overfilling is a problem when the oil level becomes high enough to reach the crankshaft. The oil can be whipped into an aerated mixture reducing the lubricative properties. Although you can overfill to some degree (because one can assume engineers build in some sort of variable margin of error) there could be an increased chance of incidental oil-to-crankshaft contact over uneven terrain. In my opininion, an overfill that does not result in crankshaft contact will not affect oil pressure as the system is normally designed to pull from a ‘reservior’ at an established rate.

The same principles apply for ATF in automatic transmissions when oil levels can be high enough to contact the transmission pump.

[Joe Mama]

Sounds legit… pretty good price for a 6.3qt. synthetic oil change.

You can save about $20 doing it yourself but then you have to deal with the mess and oil disposal.

[Author]

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