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Mercedes-Benz 420SEL Problems

Rubber boot connecting throttle body to intake manifolds may crack on Mercedes-Benz 420SEL

Problem Description and Possible Solution

The rubber boot connecting the throttle body to the intake manifold tends to crack. This can cause hard starting, rough or erratic idle, and engine performance problems.
(4 people reported this problem)

Mercedes-Benz 420SEL Vehicles With This Problem

RepairPal Verified
Average mileage: 225,200 (200,400–250,000)
2 model years affected: 1990, 1991
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Brake problem? Or maybe a faulty head gasket cylinder?
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Viewing 1-1 of 1 comments
Came on slowly, until could not hold an idle at stop lights. Sound from under air cleaner is a loud whooshing sound like a vacuum cleaner. Also, I sprayed carb cleaner at the boot and the vehicle accelerated.