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2006 TJ Gorgeous Outside - Very Rusty Underneath - What happened ?

3.4K views 15 replies 7 participants last post by  steve0530  
#1 ·
Hi guys, I went to a place yesterday ready to buy a TJ that it looks well maintained from the outside but I had my doubts when I was looking at the pictures underneath this jeep. I took the trip anyways. The body looks awesome however I was very stunned when I opened the hood and started to check the engine bay. On the passenger side the small block (I think) looks all rotted. Is that the block ? What happened there, why this bottom part of the engine is like this ?
I ended up passing on this jeep with apparently only 65k miles. Im still thinking about that.
The pictures are a close up of the rusted area.
Vendor said they changed the oil the day before but when I got there the oil filter looked old. Not a good feeling.
To me this jeep was sit under water for a while. It seems impossible to me that this rust is from just driving I wondering if Sandy knows anything 😁
 

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#2 · (Edited)
That happens on vehicles that actually get driven. No big deal. The engine block is cast iron and very thick. What you see is just a paint flaking and surface rust. Easily cleaned up and painted, if it bothers you.

As long as the frame and body are not rusting through, what you see on the engine is really just cosmetic.

Looks like a dealer has it. Those can go two ways...1) They think they can get rich and ask an arm and a leg for it... or... 2) Make a silk purse out of a sow's ear but covering up things like rotted frames and rot with undercoating and fresh body work.

Send pics of the frame and under the body to confirm what it looks like underneath. If the price is not sky high, this might be one to look at a little further.
 
#11 ·
Thanks for your post. Would you mind taking a look out here : They have plenty of picture. They were asking 20,200, I dont think its worth that kind of money.
Let me know
Thanks
 
#4 ·
Way too rusty for me, I live in Texas and not on the coast, so rust like that would be a deal breaker. We don't salt roads in Texas, as far as I know, but we do use sand when it ices over, one or two days a year at most when needed. I think the pics you took are worse then some think they are, that's just the way I see it.

trainman
 
#7 ·
Way too rusty for me, I live in Texas and not on the coast, so rust like that would be a deal breaker. We don't salt roads in Texas, as far as I know, but we do use sand when it ices over, one or two days a year at most when needed. I think the pics you took are worse then some think they are, that's just the way I see it.

trainman
Engine block rust is really zero concern.
It is frame and body rust, that is the killer!

My engine block looked identical to the one in the first post here. It is cast iron. I have never seen a cast iron engine block be compromised by surface rust. Cracked from heat or damage caused by other factors, but exterior rust was never anything to even think about as an issue.

I scraped the scale and ran a wire brush on my drill to clean to the metal.

I don't have a "before", but trust me. It looked just like the one above. Paint flaking off, bubbles of rust.

Here is after brushing clean...
4506577


Here is the "after" a little high-temp engine paint new... It probably didn't look that good coming out of the plant to begin with!
4506578
 
#5 ·
Ask the dealer to pull the OPDA sensor so you can look at it, that bolt will not easily be removed. May as well have him pull the OPDA for inspection. I imagine the OPDA holder bolt would be very difficult to remove as well ... RUN AWAY....
 
#6 ·
Dealer selling this is not likely to be willing to pull the OPDA for you. If the frame and body are clean and the price is right, leave a deposit and bring to an independent mechanic you trust for detailed inspection. You'd want to do this, anyway.

Don't tell the seller your mechanic is going to pull the OPDA, just tell the seller you are taking for mechanical inspection by your shop. Once at your shop, you can ask your guy yo pull the OPDA and have them inspect the cam gear the OPDA is driven by. If they can do that for you, they will want to see if the gears are good or chewed up to hell.

If the gears are chewed up, the engine would not be running all that great and would probably be able to hear that something is off while the engine is running.

If the mechanic can't go that deep, they can check everything else and give an opinion on what shape it is in. If it is not making any weird noises and runs good, chances are fair the original OPDA is fine for the time being.

You would want to replace with a new Crown OPDA anyway, which less than $200 for the part. Keep and use the old sensor (the wired part that plugs in to the side) that is in there now with the new OPDA unit. The originals seem to not throw codes like the new senors. DO KEEP the new sensor and the old OPDA on your shelf for an emergency spare, if something unexpected happens. You can always throw in that spare, while waiting for another new part to be shipped.
 
#8 ·
That Jeep looks like like my '03 Rubicon when washed. I had the exterior totally painted in 2018 and with the new clear coat it really shines like that. I have had people ask me how old it was because they thought it was only a couple of years old. However, even at the ripe age of 18 it doesn't look that bad under the hood. But then the first owner took good care of it for 11 years and I am keeping it under cover as well.

I would say the Jeep has been painted. At a minimum it is 15 years old and if it had been garage kept it would look like that on the outside, but would look good underneath as well.