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Pat
01-09-2007, 09:49 PM
Has anyone ever seen this? Any idea why it may have happened? The firewall has a number of cracks right around where the firewall turns back towards the exhaust tunnel. I also noticed that the car has bolts running through the ears on the frame rails on either side up through the floor. I bought this car just recently and it drove fine. I know the right side of the car has been painted before, so it's possible that it's accident damage of some sort, however, I'm now more curious about the bolts through the frame/floor.

Any input, suggestions, comments?

mpgmike
01-09-2007, 10:25 PM
With only pictures to go on, here's my guess. The car was originally NA, as there is no heat shield against the firewall. Somebody either converted it, or removed the heat shield along the way. When it was impacted, the sheet metal cracked from the thermally stressed weakening.

Mike

Tony Hanna
01-09-2007, 11:05 PM
I'm with mike about the cracks being heat related. It's the bolts through the frame rail that get me. That's pretty odd. I mean granted mine has a weld right there, but that's because I replaced a sizable chunk of rusted floor and wanted to tie the patch back into the frame for strength.
Is there any indication that the floor has ever been repaired? I can't really tell from the pics. If not, then maybe the frame rail has been replaced and they bolted it through to the floor instead of spot welding. That's the only thing I can think of.

turbovanman²
01-09-2007, 11:06 PM
I see it all the time, my van has done it and other TD's I've worked on. I believe its the flexing of the Unibody. Mines bracked and use a strut bar and it still did it. All I did was drill at the end of each crack so it can't spread and welded it. Hasn't cracked again. Fixed the other cars the same way and didn't come back.

Pat
01-09-2007, 11:10 PM
I haven't found any accident damage on the floor yet, although I'm now looking the car over very closely. It's a '92 Iroc R/T, so there was a heat shield at some point (I have it...came with the car), but I don't know when it was taken off.

Simon...did you get those hoses yet? PM me.

JDAWG
01-09-2007, 11:38 PM
bolts deff dont look stock to me, but i have seen worse come out of Chryslers productions lines. Was it built on a friday?

BadAssPerformance
01-09-2007, 11:46 PM
Wow, never saw anything like that before... and I have seen some tweaked TM's!

rare_ram
01-09-2007, 11:48 PM
The car was probably rode hard and the bolts added to repair seperation of the floor from the unibody.

racer-xerols
01-10-2007, 12:57 AM
I agree with the consensus - it doesn't look like accident damage. The floor is straight, the frame rails are straight...they look like they were just.....bolted together for some reason. Does the car creak or rattle more than usual? Might have been an attempt at a unibody noise "fix" at some point. At any rate, they look like they've been in there a while, and the metal all looks pretty OEM / stock as far as overspray and undercoating. What's the spacing? Was the car ever raced? Could be they're leftover from an old amplifier installation...or a racing seatbelt harness anchor...

The cracks...odd. Do they lead to or from anywhere? Like, one end at the K frame mount? I think it may just be bad metal. The cracks are just cracks, not burst apart or anything that would indicate accident. Usually if there's an impact, the halves of the cracks wouldn't line up, they'd be far apart on one plane or another. This just looks like metal fatigue. Throw some Franken-stitch welds on there, install the heat shield, and go racing, LOL.

Turbodave
01-10-2007, 10:55 AM
I've seen cracked firewalls like that a lot on cars, primarily on Daytonas, but it seems to be a possibility for all body styles. Not sure why, I've noticed them on TBI cars as well as turbo cars, and on accident free cars as well.

Those bolts through the frame rail are unusual.

88_pacifica
01-10-2007, 11:01 AM
bolts deff dont look stock to me, but i have seen worse come out of Chryslers productions lines. Was it built on a friday?

Nope... the Monday after New Years.. :D

JDAWG
01-10-2007, 11:51 AM
possibly there were super small rust holes where the bolts are. Prev owner drilled it out bigger and put in bolts and undercoated/painted over. That is a common place for rust seems like.

Hemlock
01-10-2007, 07:27 PM
The bolts through the frame are supposed to be there. My IROC has never been touched and it has the exact same bolts in the same places.

Tony Hanna
01-10-2007, 07:39 PM
That's really strange. I just replaced that section of floor in my Sundance and it was all spotwelded. No bolts.

Pat
01-10-2007, 11:28 PM
Thanks for all of the info everyone. I'm not going to worry too much about it. I can weld up the cracks when the engine is out and clean it up some.

Pat

glhs399
01-10-2007, 11:44 PM
http://i47.photobucket.com/albums/f163/glhs399/Picture201.jpg :yuck:

This happened on a 88 CSX-T. It was a old road race car that I was told was running 500 lbs. spring up front! It just had a bolt in roll cage and none of the suspension points were reinforced or tied into the cage. So I could see how it happened!

Doug Folsom
Hillsboro Oregon
dirtydrifters.com

85 GLH Rally Car
86 GLHS #399
88 CSX-T (no budget rallycross car :thumb: )

BlueBaron
01-11-2007, 05:13 AM
That picture above is a dead ringer for my car. I'm running Mopar road race springs/shocks and had a rotted K-frame. The 1-1/4" sway bar was really the only thing that held the front end together.

amcpacer
01-13-2007, 01:00 AM
My Daytona has the same kind of cracking on the firewall. I have taken excellent care of the car and it has no rust. Never been in an accident. No heat issues either. I think it must be a faulty batch of sheet metal. I am not looking forward to fixing it. I thought about sanding down the metal near the cracks and using JB weld to stick a new piece of sheetmetal over the cracked areas.

BadAssPerformance
01-13-2007, 01:05 AM
Probably best to TIG weld a steel strap across the crack to the back of the firewall and fill as needed on the enginebay side so that it is invisible.

What years are the cars that everyone is seeing these cracks on?

whywoody
01-13-2007, 02:00 PM
My '89 minivan has 2 long mirror image cracks also running down under the firewall,looks like fatigue rather than anything.I am pretending they are not there lol,as they look like they have been there for years and aren't getting worse.The van's shell is getting very rusty,so I'm not putting much effort into saving it.

shelbyplaya
01-18-2007, 01:02 PM
cuple of my daytonas have the same cracks, but mine are up higher

MiniMopar
01-18-2007, 05:07 PM
My Daytona had a lot of cracking in this area, but it had been punched in the nose and the K-frame. I MIG welded the cracks and then welded plates over the area on the inside. It's a stress point and it's just sheet metal. Cracking is not surprising.

My 87 CSX has a couple of cracks starting too.

CDNTurboZ
01-18-2007, 11:17 PM
My 86 t-top daytona had a small crack on the firewall, when the floor was fixed I got the crack welded up.

Yet my two hardtop 86 turboz's had no cracks though...probably due to the t-top body flex then.

Aries_Turbo
01-22-2007, 10:33 PM
its unibody flex. our cars arent the stiffest vehicles so they crack when they flex over bumps and stuff for 100000 miles. you should see the rockers at the base of the B pillar on my 2-door k cars. they are cracked from the flex (outer sheetmetal). Neons crack on a spot on the firewall too when autox-ed and raced hard. common problem.

solution? cage or many small reinforcements and additional small metal braces here and there. stich welding seems to help too.

Brian

87csx2.4
01-23-2007, 10:49 AM
Yep I bought a lebarron for my son and I noticed I could actually feel the accelerator pedal moving around while driving.The cracks look almost Identical to those I welded them up and good to go.

Rick
02-05-2007, 05:43 PM
My educated guess for the bolts is they were part of the “frame rail welds” recall. The recall was launched on October 8, 1993 and was listed as recall number 587. Both my IROC R/T's were part of the recall.

amcpacer
02-07-2007, 03:33 PM
My daytona is an 86 non t-top. The cracking on my car is getting quite severe. Last night when I was driving the car was making all sorts of clunking sounds and I could feel the clutch and brake pedals move up and down slightly. The gas pedal is moving around as well. I hope I wont have to scrap out my car because of this. When I drive on dusty roads the car fills with dust as dirt comes flying in all of those firewall and floor cracks.

amcpacer
03-07-2007, 02:33 PM
Actually today I found out 2 of the big bolts that hold on the K-Frame were really loose and about to fall out. I tightened them and now the car feels solid and quit making clunking sounds. Plus the pedals no longer seem to flex. How odd! There are still cracks I need to fix to keep dust out of the car.

The loose K-Frame is probably why it cracked in the first place. Perhaps your situation may be similar. Now I just need to find someone to weld up the cracks. From the interior or exterior?

shelby zed
03-10-2007, 09:55 PM
those bolts are to hold your floorboards in so that when you your laptop says "danger to manifold" and you hit nitrous your floorboards dont fall out. ;) (see fast and the furious 1)