Coolant and Tiptronic Gear Box Oil Intermix

[Hog997]

Hello all,

This is my first post, but long time lurker. I look forward to contributing moving forward, and also having all your experience help me.

I’ve searched for this topic and can not find my specific issue, so here goes.

2007 997.1 S, 58k, clean overall and I am a stickler for proper maintenance.

Problem started when I noticed a small amount of oil substance in my coolant reservoir, minor coolant loss, and clunky hard shifting in all aspects.

Long story short, my very qualified shop discovered that the transmission oil cooler has a pretty good dent in it, about 5 layers of cooler sections across. The oil in my coolant reservoir is too light in color, and doesn’t cling like engine oil. It’s trans oil. We’ve determined that in the cooler being damaged, intermix has occurred and needs to be addressed. This issue is no more than 300 miles old.

Car has no other issues, besides a failing water pump to be replaced. We do not think this is a blown head gasket. Motor oil does not show coolant, no other “engine” related symptoms.

I trust my independent mechanics skill, and they are very reputable and well known. I don’t question their diagnosis or desired fix, but just wanted to put this out to the group for feedback, and reassurance/sympathy.

THE PLAN:

Coolant system to be completely drained, cleaned/flushed as much as required, refilled with new coolant, vacuumed down.

For the trans cooler...

Trans cooler to be replaced.

We are worried about the long term affects/damage that’s been done from the coolant being in the transmission case. So first question is, what are your thoughts on potential gearbox damage already done from the coolant/trans oil mixing inside the gearbox? Life expectancy? Failure rate? Other thoughts?

The fix is to drain and fill the transmission per the proper procedure, perhaps several times with filter changes each time, with the intention of getting as much of the coolant out of the gearbox as possible. I understand that a “powered flush” is not possible on our cars, and that a complete exchange may never happen. We are hopeful, with the coolant being heavier than the oil, that most will settle and come out first (yes I know there are nooks and crannies). The end result besides the clean out, is to essentially complete the 60k trans fluid flush, filter and new seal by the time we are done. So second question is again general thoughts and feedback as the perceived success rate of this plan, success being a transmission that will last for the forseable future and free(ish) of coolant.

Third question/comment is to ask if this work and expense is pointless? The gearbox is toast, and consider a rebuilt transmission as the better idea? My tech does not feel we are at this point. I get big boy rules, and we need to pay to play, but I don’t really have the funding to do the rebuild at this time (7-10k).

I do want to stress again that my shop is extremely competent with P Cars, and this post is not in doubt of their plan. I’m actually very confident, and hope that it prevails. My only intent is that perhaps someone is out there, who has been through this and can add something worthwhile.

So thank you again for all of the constructive feedback and shared experience/opinions.

[Jeff Alton]

My suspicion is that flushing the gearbox will be successful. Was the coolant level low? Have you drained the transmission yet? If so, what did the fluid look like?

You don't have many options here. Follow the "plan" your shop suggests (not a lot of work in the big scheme of things) or replace the gearbox and still do some of the "plan" to get the oil out of the coolant. Let them do their thing and you will likely be just fine.

Cheers

[Hog997]

Hi Jeff, I really value the comments.

Regarding the coolant level, it was aprox 1cm below the low coolant level line, at its lowest moment in the reservoir.

We will be draining the fluid this week, and I will report back as to the appearance. We are also pulling a sample for proper testing and analysis. Within the coolant res, the oil has to my surprise varied in volume. At is lowest, 10-20 droplets, and at the most, a thin layer atop to coolant across the visible parts of the coolant reservoir.

As you suggested, the coolant system will be cleaned/flushed and replaced regardless of the other steps taken as part of the plan.

Cheers,

[yelcab1]

You trust your shop? They see the car, they touch it, feel it, run tests on it. Or do you trust a bunch of arm chair experts who don't know the car, or you from adam?

[Hog997]

Originally Posted by yelcab1

You trust your shop? They see the car, they touch it, feel it, run tests on it. Or do you trust a bunch of arm chair experts who don't know the car, or you from adam?

I appreciate what you are saying yelcab. If you were to reread my comments, I think you’d find that my post was in support of my shop, who I trust more now than ever. You’ll also find the comment “perhaps someone is out there who had been through this and can add something worthwhile”.

[kevingross]

As to the transmission's condition, I suspect it will depend on how much coolant invaded it, how long it was there, and how hard the car was used while the issue existed. Unless there is a warranty in place, I suspect it will make sense to flush the transmission, drive it, and see how things go. Good luck!