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Well the sniffer consistently picked up refrigerant at the rear evap core (near the expansion valve which is near the rear RH tire). It’s a very small leak but it did consistently pick up a signal. I’ve begun tearing out all the trim panels and will hopefully be able to give an update when I’m done.
In the video Eric didn’t leak test to see exactly where the leak was coming from. I do the same thing in similar situations when I’m working on someone else’s car, but since this is my car I’m going to spend the time looking into it. I may not actually have to replace any parts at all. There are 4 connections/o-rings in the expansion valve so I’m going to try and pressure test everything and see if it’s just a bad o-ring.
I watched the first one and Eric made a comment about leaks at the rear evap core being common. It was nice to see in the video that the rear expansion valve is so easy to access. I’ll try and check around that expansion valve tomorrow and report back what I find.
[quote=”college man” post=181987]Actually an exhaust leak will cause the p0133 not the other codes.[/quote]
+1
Fix flex pipe then clear codes and recheck codes once the O2 monitor has completed
Since the sensor is in the front the wiring should be pretty accessible…just follow it into the engine compartment and see where it goes. It doesn’t look like that replacement harness is made to replace all the wiring from the sensor to the ABS module but rather the wiring around the knuckle (which is usually where breaks occur)
Ok that’s what I figured…although new parts are sometimes faulty the chance of that is so small that I think you really need to start focusing on wiring integrity. Since you put in a new hub/bearing with a new sensor inside of it then like I said I think it’s time to start focusing on wiring.
[quote=”nightflyr” post=181560]Just something else you may want to look at …
Check the tone ring.[/quote]Yeah that brings up a good question. I had assumed that when he said bearing/hub assembly he was referring to the gm style with an integral tone ring since he replaced the whole bearing assembly just to address a sensor issue. But for clarification is your tone ring external (i.e. on the axle) or is it inside the bearing along with the sensor? If it’s actually external then look at the teeth on the tone ring and see that they are uniform and free of rust or other ferrous flakes & chips. Also if you do have an external tone ring and sensor the air gap is absolutely critical. VRS rely on magnetic field strength which is exponentially proportional to distance (I believe I’ve got that right). What that means is a small amout of change in distance greatly changes magnetic field strength. Anyway, increasing the distance even like 1mm or less from spec can cause the signal to be too weak for the computer to read at low speeds. Rust jacking of the sensor is a common cause of too much air gap.
One other thing…when you remove the actuator use your finger or a screwdriver or whatever works to manually move the blend door position. First it will tell you whether or not the door is jammed and second it will tell you if proper placement of the blend door will fix your problem (one you move it into position turn on the HVAC and see what results you get).
Also with the actuator still plugged in and it’s shaft partially removed you may be able to watch it in action to see if it has stripped gears and if it’s capable of a full range of motion.
[quote=”DaFirnz” post=181552]GM cars of that design still use 2 individual wires for the ABS sensors, as opposed to the 2 wires in a single insulator that most other ABS systems use. This makes them very susceptible to breaking along the control arm up to the subframe, where they no longer move with the suspension. These wires will be in the cheap plastic wire sheathing.
Unplug the sensor terminal, remove the sheathing from the wires back to the subframe and look for breaks. Repair any breaks and go from there.[/quote]
That’s great info! Let me also add that the copper strands can actually break inside the insulation. One way to test for this is to give them a good tug in different locations and see if you notice the insulation stretching anywhere. Since your problem is intermittent you may not see a full blown broken wire, but rather some very very small break that is intermittently making connection…so look very closely. Also please report back what you find. A lot of people on forums never come back and finish the thread with a conclusion.
Yeah the PP4 is great! I don’t own a hook but have heard complaints of them being bulky and slow (specifically in the auto detect/ranging function). I honestly see no reason for the hook since I can accomplish everything it does with other electrical diagnostic equipment that I already have.
That’s good to know that there’s a fuse in that big bulky connector. I always wondered why it was so bulky. If I ever blew that fuse you better believe I’d cut that connector open and replace it before buying a new one…or bypass it and add an exterior fuse. I hate when manufacturers go out of their way to make things non-serviceable so you have to buy a new one or send it in.
It definitely sounds like you are going in the right direction…is the actuator easy to get to or is it like you have to rip the entire dash off just to get a look at it?
Ok I feel that at the bare minimum you will need a multi-meter in order to investigate this problem. It’s cheaper in the long run to invest in diagnostic skills and equipment than to swap parts. I’m glad to hear that you’re investing in hand tools, but I find my multi-meter gets used at the same frequency as many of my hand tools. I really don’t know what I’d do without one.
You can get a multi-meter pretty much anywhere (even wal-mart). If you want to make an investment in a nice multi-meter then I would suggest a BK Precision 2709B. I think this is one of the best multi-meters for the cost I’ve come across. To really get into what makes a multi-meter much better than another one I’d probably have to write too long a post, but the short answer is things like speed, min/max function (really useful for automotive), lightning quick continuity beep, backlight that doesn’t time out too quickly. Those are just a few. Unlike many many multi-meters out there I can tell that the person who designed the 2709B really understands the type of functionality needed in the real world.
Whatever you end up with…I feel that we will need to get some hard evidence (via electrical testing) before any of us could give you any further advice.
First tell me what kind of equipment you have access to. My assumption would be a multi-meter, but not a scope or scan tool with ABS live data…is that correct?
Mystery solved…there are two molded rubber hoses that fit absolutely perfect in the wrong place. The guy who did the clutch hooked them up wrong and when the owner complained of it running rough…rather than looking into it he claimed he didn’t do it and it was the spark plugs :blink:
Turns out there are two evap solenoids right near the air box. He hooked these solenoids together with a hose. When actually, the lower one gets hooked into the air box and the other one (purge/VSV) gets hooked up to the mystery hose that runs just behind the throttle body and connects into he intake.
It was a really tough vacuum leak to find because I suspected it may be internal but after pinching off the PCV hose and nothing happening I moved away from that direction and started to look for an external leak where I could hear the hissing :dry:
The car is gone for the day so I can’t look at it right now, but I’m getting it back tomorrow. Found another picture online of an 03 that may indicate that this hose should actually connect not to the airbox but to what looks like the purge solenoid. Tomorrow I may get lucky and find a vacuum hose diagram sticker under the hood (should a looked for it but I guess I was rushing around too much).
Although that still doesn’t explain why there is a nipple on the air box…could it be for some kind of accessory that needs a vacuum port and if the accessory isn’t there maybe the port should have a cap on it?