Hello,

I have an '88 4runner with 186,000. I love the truck and I am slowly making modifications to it as time and money allows. I have noticed that since the winter season started there is a loud whistling noise at cold start ups. It seems to "go away" as it warms up to running temp but unfortunately it also seems to be getting progressively louder and takes a longer time to "go away". I thought that it sounded like some kind of vacuum leak, but I can't seem to find it. Could it be something else, and do you have any ideas of what it might be or how to diagnose it. I would like to have the truck for a while and I don't want to ignore a possible current/future problem.

Thank you very much!!

Zuff