Odd engine noise, '95 SVX

[MG McAnick]

I bought another SVX at an auction last week. For that reason, there was no guarantee. Now I'm hearing a noise that sounds as though it's in the bottom of the engine. It does not sound like a ''normal'' rod or main bearing knock, although I can't rule that in or out until I hear from you all. The noise starts at about 2500 RPM whether sitting still or under load. I had thought it went away at higher RPM, but now think it's just masked by all the other things going on. There is no indication of low oil pressure like I think there would be if it had a bad rod or main bearing. Has anyone else ever experienced such a noise in an SVX? If so, what was it?

[SuBrat84]

Yes. My 94 is horrible. It got worse after i ran 100 octane in it. now it does it at idle and anything below ~2500 rpms. It used to do it just under 4k rpms.. I'm not 100% on this.. but I think what it is, in the cat converters and / or resonator pipes there is stuff coming loose.. so it's kinda like a metal rattling noise that is affected by how much exhaust pressure there is. i intend to gut my cats and resonators to see if this fixes it. Another slightly more expensive option would be new exhaust. Again, I am not POSITIVE this is the problem... it could have something to do with exhaust valves or ????

[MG McAnick]

I crawled under it today with a stethoscope. I think we can be certain that the noise in not coming from disintegrating catalytic converters, but for the life of me, I can't tell where it is coming from. The oil is coming from the front seal, so it's a candidate for new timing belts at the same time as that job is tackled.

[nipper]

Remove one spark plug wire at a time and see if the noise changes pitch. Is it from the front center or rear of the engine. Does it do it when the engine is cold?

 

nipper

 

PS i love svx, looking for one for myself. There is an svx board, but they are sort of useless as far as anything thats not the tranny or the differentials.