I have an oil leak – is it the RMS or IMS seal or is it something else?


If you own a Porsche 986, 996, 987 or 997, we’d say there is a very high probability that you’ve heard about the RMS or IMS.. now, on the 986 and 996 (none Turbo) models, the most common oil leak is the RMS (Rear Main Seal).

RMS Main Seal

Rear Main Seal

This seal has been modified several times over the years and it’s imperative that you fit the latest seal with the latest RMS tool, if you don’t, then there is a very good chance it will leak again.

RMS Tool

RMS Tool

If it’s not the Rear Main Seal that is leaking, then it’s a good chance it will be the IMS seal. This is not to be confused with the IMS bearing, some people are led to believe that when this seal has been replaced, that this means the IMS bearing has – this is obviously not the case. The IMS seal is also a cheap part, weighing in at around £10 + VAT. It sits on the flange housing shown here..

The IMS Solution

The unfortunate thing about having to replace these seals, is the labour involved. The transmission housing needs to be removed to determine which seal is leaking (and also to replace it). The IMS seal takes slightly longer as the timing needs to be locked too.

Here is a video showing ‘someone’ replacing the Rear Main Seal using the correct tool.