Finally got the '92 Jetta GLI going and have been adding the miles all week. What's baffling me is that I can't tell if the ride of this car is just really harsh, or if the shocks are totally shot. From the (admittedly asinine) "bounce test," I would expect to see EXTRA bouncing and instability from a corner of the car with a blown shock...but this thing rides like the springs are nearly rock solid every time I hit a bump. I've thought about replacing the shocks/struts anyway, simply because I have no documentation proving it's been done. But does this not sound un characteristic of blown shocks? Or is it a possibility that they are just totally gone? Is it overdamped? Or are the springs just really f'ing stiff? Bueller?
Are they adjustable? Too much compression will feel like hitting a solid. Is it lowered? Maybe you are riding the bump stops?
Suspension is completely stock VW "factory sport" and non-adjustable, to my knowledge.
The car sat for about two years before being revived, if that makes any difference.
Without knowing the mileage on it, I think it's still safe to assume that after more than twenty years, the stock shocks are blown.
Time for an upgrade!
I'm thinking overdamped. Blown shocks have oil leaks and comical bouncing. Just making my rear shocks slightly underdamped in one direction with preload caused noticeable bouncing.
Seized shocks feel a lot like overdamped shocks though. If the car sat immobile for 20 years that might have happened. It's easy to diagnose though, you just jack the car up and make sure the suspension moves.
One of my old Fox Mustangs had original 100k shocks on it and it rode like absolute E36 M3. I put a set of Koni Reds on it and it was suddenly a Cadillac by comparison. So yes, in my experience, worn-out shocks can cause a bad ride.
I had a blown rear shock on my scooby that would act somewhat intermittantly. Some of the travel would be undampned and then hit a region where it regained function. It felt kind of like you mention going down the highway over bumps, move freely then like hitting a bumpstop. (I think some fluid had leaked and what remained didnt allow full functionality or something like that)
If you can have the car down for awhile, is just pulling them to put it through its range of motion practical (to see if you need new stuff). Although, with the PITA, its pretty much practical to replace them anyways.
Alternatively, get a few larger friends to bounce on an end of the car and see if it feels like it hangs up suddenly through movement or just resists movement. (when doing this listen for what sounds like bubbles forced through restriction, it wont be loud, but will tell you that its doing as I mentioned)
Essentionally, bounce test with fat guys looking for smooth motion.
My Miata came with one or two blown shocks. One front corner appeared to be OK, and I know the other one was blown. I'd hit the brakes, and it would dive forward and to the left a bit. Then I'd let off the brakes and that corner would continue to oscillate up and down for about a second. It was easy to tell. But they were toast and probably had 100K+ miles on them. They were probably all bad but at varying degrees.
I used to be able to bounce my rear end on the rx7 like a basketball, also so much to the point where you can physically watch the caster change.
Just drive it over a speed bump.
If it bounces more than once.
