Freelander 1 Exhaust rattle

I replaced the mid section and silencer on my freelander this weekend. All went fairly well however there now seems to be a rattle at certain RPM.

I've gone back under the car and shook the mid section, none of the exhaust seems to be hitting the sub frame or anything like that so I'm a bit perplexed as to what the noise could be.

I tried hitting the midsection and then the back box and hitting the back box seemed to cause a similar noise but I wasn't 100% sure where it was coming from.

Has anyone had anything similar? If I had to describe the noise it I'd say it was a fast fairly high-pitched rattle that only lasts a short while.

have you checked the cat as it has a heat shield on the top and they often come loose it will just require a tack weld if it has.

Or is the heat shield on the new back box resonating?
The other mount that can break is the bracket on the ird casing if it has one?

I've come across this with cheap after market exhausts.
OE or quality makes are generally free of such issues.

Thanks for the replies chaps, I looked for the IRD mouting but mine doesn't have one (at least not what I could see). I'm thinking @Nodge68 might be onto something because this exhaust was incredibly cheap from ebay - £56 delivered for mid and back box. Can silencers get damaged in transit?
I'll get under the car again after work and start tapping with a rubber mallet and I'll double check the rear cat, I'm pretty sure I would have noticed it before though if there was a problem with the existing system and I've not messed with anything further forward than the mid section.
Do you think it'd be okay to take the rear silencer off and drive it round the block to see if the noise is gone? Shouldn't cook anything or poison me for a short journey should it?

At £56 I expect it's got a loose baffle in it. This will resonate at a set frequency, hence the noise.
Get a helper to hold the revs where the rattling is worse. Then try to locate where the sound is coming from.

Thanks for the tip @Nodge68 I'll try that out this evening.

I've got the rear silencer off at them moment and realise my plan of driving it without it won't work as the midsection would be resting on the sub frame.

However what I've discovered is that there is water in the silencer!? I shake it side up side and it makes a sloshing sound!? Surely that can't be right!?

If the engine has been run for short trips. Then water is very likely. The exhaust gas contains CO2 and water. Huge amounts of water vapour are a byproduct of combustion. The water vapour condenses in the cold exhaust box. So if only short trips are made, it never heats up enough to dry the boxes out.

The plot thickens! I think I might have found the cause!



Really oddly like I said earlier I've not touched this section of the exhaust but I think this might be the cause. I'm just in the process of dropping out the under tray to see if I can remove it.

Think I'll be able to source a replacement?

Took the heat shield off after taking out the under tray and it was indeed the cause of the rattle!!!

Now to source a replacement! Any idea what its call other than heat shield? Or should I not bother? It looks like its maybe there to divert any oil away from the exhaust?

I have not seen one of those heat shields before that just goes over the pipe strange?

teddywood1 said:

I have not seen one of those heat shields before that just goes over the pipe strange?

Click to expand...

It is odd isn't it, I can't imagine it shields much heat... None of the replacement rear cat pipes on ebay seem to have it either! The pipe itself is not too bad, it's plenty tarnished and discoloured but the integrity of it seems plenty in tact.

In regards to the 'heat shield I could possibly clean it up and bolt it back on. Here are some photos of it after removal:

Just bolt it back on, with new bolts if necessary. The heat shields are designed to reduce infrared heat energy from reaching sensitive components nearby. So it's best to refit it if possible.
At least your budget exhaust is free from unwanted noise.

Yeah I'm pleased about finding the cause! Be nice if I could find a new shield to replace this crusty one but if I fail to find one I'll bolt this one back on.