Cracks between turrets and firewall

[afterburner]

Today I was working under the bonnet when I noticed that around both of the turrets of my B4 I could see cracks in the seam sealer that are where the turrets meet the firewall (the seam sealer is in the 90 degree angles between a turret and the firewall)

They are present on both sides, go almost non-interrupted for about 20-30cm in length starting on top of the turrets (where the top mount caps sit) and go around the turrets down the firewall.

I haven't noticed them before, but this doesn't mean that they weren't there. They are less then 1mm thick, mostly hairline at most places.

Should I be worried or is this something that happens because the body flexes and the old seam sealer with hard paint on top cracks?

I have delrin control arm bushings, solid aluminium subframe bushings, stock springs and koni front shocks only one click away from the softest position. It's harder than stock but comfortable setup, no harsh hits when going over bumps.

It's also a 4 cylinder engine, so not that heavy. I am not the person that goes easy on their cars, mine is even lifted, but then again, I haven't done anything that hard to the chassis to crack it...

[UrS4boy]

Today I was working under the bonnet when I noticed that around both of the turrets of my B4 I could see cracks in the seam sealer that are where the turrets meet the firewall ....I have delrin control arm bushings, solid aluminium subframe bushings,

Where do you think the energy that used to be soaked up by rubber bushings and subframe mounts went to?

It got transferred to the chassis, causing the cracks. Maybe cracks in the tower seams themselves.

There are reasons why race/track cars running delrin control arm bushings and solid aluminium subframe bushings double-weld existing seams.

[afterburner]

I agree, it has to go somewhere, but a lot of the guys here are driving with the same setup and before I decided to go that route I researched all the opinions and what people had to say about those bushings... I didn't find anyone having similar problems. Does anyone know what's underneath the seam sealer? I want to find if there are any actual cracks in the tower seams, but I don't know where exactly to remove the seam sealer and see what's happening underneath it. Might double-weld the existing turret seams at the end if it's necessary.

[afterburner]

BTW I also have a tunnel brace (a la Error404's tunnel brace, if I am correct in remembering that he made one) + big fat custom strut brace, which should hold stuff in place... but probably I need also some bracing between firewall and turrets...

[jaychen]

Having done seam welding on a heap of S13's and similar Jap cars, you usually just use a chisel or a sharp paint scraper and go to town on it.

Not sure whats underneath on these cars but on those it's just some spot welds along the way.

[Kieron20V]

My coupe has this. dont think its anything to worry about to be honest, ignore the rubbish above. its just the sealer and paint thats cracked, the metal underneath is sound. Just lots of heat cycles and vibration over the years causing it to go brittle and come away from the metal.

Im not worried about it, dont think you should be either.

[jaychen]

My coupe has this. dont think its anything to worry about to be honest, ignore the rubbish above. its just the sealer and paint thats cracked, the metal underneath is sound. Just lots of heat cycles and vibration over the years causing it to go brittle and come away from the metal.

Im not worried about it, dont think you should be either.

As i said,

I was referring to Jap cars.

Don't see how my post was rubbish.

You're right, it's still joined underneath the sealer.

[UrS4boy]

ignore the rubbish above..

Assuming you are directing the above comment at me, my brand of "rubbish" is always always going to be the "Better safe than sorry" kind of "rubbish".

Erring on the side of caution is always safer than living in denial/ignorance of a potential problem.

If it was me, I would peal back some of the cracked sealant at the towers to check for cracking and/or rusting at the seam between the towers and chassis members.

[jaychen]

Assuming you are directing the above comment at me, my brand of "rubbish" is always always going to be the "Better safe than sorry" kind of "rubbish".

Erring on the side of caution is always safer than living in denial/ignorance of a potential problem.

If it was me, I would peal back some of the cracked sealant at the towers to check for cracking and/or rusting at the seam between the towers and chassis members.

think he was referring to me..

but either way. I'd be investigating it rather than being ignorant and paying for it later.

[rynaqui]

Ignorance is a curse, my father is like that with his tyres, 8 years old but refuses to replace them. Stubborn as a goat

[Ian Simmonds]

When we dismantled my old Audi Coupe GT back in 1999, it'd run 10 years with hard suspension and a huge front Anti Roll Bar, and there was a curved 'crack' about 12inches long right around the top of the bell housing recess. Since then, I've always stuck with rubber... (said the actress to the Bishop)....

[afterburner]

You are starting to depress me I have been running my current suspension setup for 3-4 months only. I have reserved a friend's garage for a few days next month so I can do some proper suspension work and maintenance... apparently I will also be removing the seam sealant and checking what's underneath. Might as well add some turret to firewall bracing there, just above the bell housing.

I'd like to hear more stories like this and people's experience, so I know where to concentrate my efforts when bracing the **** out of the car. I really don't think it's because of the bushings, the car is not harsh at all, I run 225/50/16 tires, also, so a lot of rubber dampening is happening...

[afterburner]

Here are some biiig pictures of the cracked areas... just for reference if someone decides to check his audi

[afterburner]

Just talked to a friend of mine who sells used Audi parts and buys old Audis and he reassured me that most of the B2/B3/B4 chassis cars he has have those cracks in the seam sealer, he thinks it's because of the old age and because a lot of the cars here in Bulgaria come from the Italian market and are from hot climates, which contribute to the cracking... but nevertheless I will remove some sealant and check for myself.

[Error404]

I very much doubt there will be any problems with the physical structure of the car.