Compression test procedure

[mickeytee]

Sorry i dont have experience with replaceing just the boots. I usually just replace the coil if its bad.

 

[travisd]

Sorry i dont have experience with replaceing just the boots. I usually just replace the coil if its bad.

How do I know if the coil or boots are bad? I could not find any cracks or tears in the boots. There no carbon trails in the boots but the boots are slightly larger than the plug and dont seal on to the ceramic but i assume that normal for this ignition system? The replacement boots fit very tight on the spark plug though. The springs look slightly tan.

Would you replace the coils from what I'm describing?

 

[travisd]

Charge air cooling system is a little bit more involved, it has you using the tech2 to cycle the electric pump.

How about procedure for changing and flushing transmission fluid and filter,rear differential and hydraulic top fluid??! Plus what fluids gm recommends currently for all 3?
Thank you!!

 

[luxuryrules]

How about procedure for changing and flushing transmission fluid and filter,rear differential and hydraulic top fluid??! Plus what fluids gm recommends currently for all 3?
Thank you!!

Got you fam. Gimme a day or two on the procedures, I’ll note that I’d personally avoid flushing the trans for me it’s just a pan drop fluid and filter change. The info about fluids we do have here:

Post in thread 'Compression test procedure'
Compression test procedure

 

[mickeytee]

Be sure to get the proper trans fluid with all the additives in it. Last tsb from gm changed what was called for in the owners manual using 12378261 with 88900330 limited slip additive.
I think it now calls for 88862624 dextron ls. There are dozens of similiar priducts.

 

[luxuryrules]

Adding some context, as Mickey observed there are some part number supercessions, for historical reference and searchability. Manual in car calls for 75w90 12378261 meeting GM spec 9986115; and 4oz limited slip additive 1052358. In attached chart, they show 89021677 and same limited slip additive. Looking up either of those numbers we can see they are both superseded by 88900401, which still requires addition of limited slip additive which has been superseded by 88900330 alt number 104003.

What I can’t find is if there is any difference between 88900401 and 88862624 (alt number 104034) Dexron LS gear oil with the limited slip additive already added. They’re both fully synthetic 75w90 gear oil that meet GL-5 spec. My ATS uses the Dexron LS gear oil, I wonder if there is any reason *not* to use the same Dexron LS in the XLR.

 

[luxuryrules]

Diff fluid replacement…. And interestingly enough the service manual does call for 2.12 quarts (2 liters) of Dexron LS gear oil

 

[luxuryrules]

I’ll be doing this job soon myself. Transmission service. It calls for removing the transmission mount nuts: there are four, torque spec is 50Nm.

 

[luxuryrules]

Transmission fill procedure and then check procedure. Check to be done when trans temp is between 86-122 degrees F, check plug torque spec is 25Nm.