I’ve got an old Suburban. It has almost 200,000 miles on it. The other day, it started acting up. I like to get opinions before I start to diagnose problems to help me narrow down the search. So, I asked my friend Pepe for his expert opinion...by telephone.
* Please note that The Hater lives in San Diego, 90 miles away from Long Beach.
Hater: Hey you know my Suburban? It started stalling out in gear. Idles and revs fine out of gear, but stalls once you put it in gear, especially when it’s hot. What do you suppose it might be?
Pepe: Vacuum leak, dog.
Hater: Vacuum leak? You sure?
Pepe: Yup, for sure, no doubt, vacuum leak. Hey Nelson, vacuum leak, right?
Nelson: Mmm...hard to tell without seeing it, but it might be. You can check by spraying carb cleaner around all the intake hoses. If it revs up, then yeah, vacuum leak. Otherwise, it could be a couple different things. Hard to tell.
Turns out, it was a sticky idle control valve and a weak distributor as well a bunch of build up in the throttle body.
Pepe: Did you figure out the problem?
Hater: Yeah, it was mostly a worn out distributor.
Pepe: No way, distributor's fine, dog.
Hater: What? How do you know that?
Pepe: Trust me, no way it's the distributor. It's a vacuum leak.
So, I replaced the distributor, the idle control valve, and cleaned the throttle body. Runs like a champ. Never did find a vacuum leak though.
And, it had plenty of coolant too.