Vibrations At Low Revs

[tomartoh]

Been looking at a cheap second car, 98 daewoo espero, like the mk111 cavelier. The owner has done all the jobs i asked of him before i agree to buy car, except car vibrates on tickover when air con is turned on. Its an auto and does it in park and in drive at about 800 to 1000 revs. when driving it stops vibrating but starts again on the over run when the revs drop. Its not engine mounts which were replaced. Anyone any ideas?

[BSJ]

Hi tomartoh, it may/may not be the a/c pump. 98 could mean it's a piston pump type a/c compressor. With wear in the bearings it could just be a flutter from the a/c crank rotation that smooths out as revs increase. It is possible for this to be amplified if it is out of sync with the engine crankshaft. But before you pull your a/c pump apart check the internal sounds with a long screw driver. Put the tip of the blade on the pump housing and your ear to the end of the handle. Compare the sounds at idle and 2500rpm. If the idle sound is coarse and scratchy, then smooth at 2500 there's your problem!

But something else could be at fault. There's generally an idler pulley which if defective can cause problems but usually would be accompanied by some strange noise.

You need to get under the hood and look for strange signs, listen too!

[goldfish]

Never rule out simple solutions, it may just be running rich due to a dirty air filter. Give the car a service first and take it from there

[tomartoh]

Just had phone call from owner to say that when new engine rubber mounts were fitted, one was fitted wrong way around [?] and in fact broke during test drive. Accessory shop open monday and garage will refit. See if that cures it !!!!

Only low mileage 87k km, owned by family since new, but dont think they went big time on service. Alternative in immaculate condition for same money is 194k km

[kartman]

194K km but well serviced and no vibrations perhaps?

[stingray]

194K km but well serviced and no vibrations perhaps?

Km in Thailand never sure. Just see the condition, but Daewoo it's actully the last car i would buy. Of corse, if it's cheap, why not, but how cheap? Prepare your self to put another 50'k for repairs during the next 6 months. This is Daewoo!

[tomartoh]

Thanks everyone for comments. Solved problem, bought a 460 Volvo