I have a 2007 Toyota Prado with the same diesel engine as the Hilux and was wondering how could you tell if the injector seals were leaking. When I bought my car new it had a knocking noise when cold, but was normal when warmed up. I had the dealer check it and he said that there was no recall, but he did recognize that it was noisy. Will I cause any damage when it is cold, someone told me that the fuel is flooding the motor causing it to run incorrectly? I am concerned that it might be something similar to the same condition after reading the article mentioned above.
There was a problem with the engines when it they were cold, I understand that it was because of over-fuelling during the time of cold running. I believe Toyota was changing the injectors on complaint vehicles. The leaking injector seals I believe us something else, and the way we know of to check if there is a problem is to inspect the oil pickup in the sump for a build-up of carbon deposits. If the pickup has a carbon buildup the likelihood is that it would eventually block and stave the engine of oil, if there is no carbon present it is unlikely to have a problem. It's best that a dealer check the pickup by inserting a probe through the oil drain hole in the sump.