Silicone Hoses

[digger]

It's happened to me! Too much stress on it + heat and movement from racing all day.

Happened with samco hoses the way

it happens on all plastic radiators, rubber or silicone. the aftermarket radiators are apparently not as good as the factory fitted ones. nevertheless heat + pressure + plastic = fatigue sooner or later. might be a bigger problem in hotter climates where temp gets a few degrees hotter

[squidmaster]

Never had the more flexible hoses cause any damage. It was a rally, so there was quite a bit more movement going on than normal. Was a 3 year old OEM radiator too. It did reach 102'F that day.

[AndrewBird]

A big problem is worn engine mounts will cause the engine to move around more than it should, pulling on the radiator hoses and either breaking the radiator neck or splitting a hose.

If you have broken a neck or split a hose, you likely need new motor mounts. Trans mounts are likely hot too.

[peytonracer4]

i have the IE hoses. if i were to do it again, i'd probably just go rubber. the big radiator to thermostat hose on top hits my fan. zip tied it out of the way (there is an oem clip) but it still rubs ever so slightly.
i have a leak now on one connection to the thermostat and a leak to the heater core.
didn't have any leaks before. so yeah... not too happy. tried tightening the clamps and doesn't help at all.

:(

[whodwho]

On leaks the silicone hoses are much stiffer by design and wont seal as easy as rubber ones, make sure the mating surface is clean and flat and not the typical corrosion covered pitted 20 year old parts.

An old trick for me on hose connections is to use Gasgacinch and a light coat on the both parts a little air dry and button it up, re-check that the clamp is tight when hot and the hose is more pliable.

[eco325iX]

I recently picked up a new to me weekend restoration project, '89 325i convertible. The PO did not have any maintenance records or knowledge of when any services were last performed, it was sitting in his garage for the last 5 years. Anyways, the fan clutch is definitely worn out and I plan to replace the cooling system components with new. Seeing that this is an old thread (2014), what is everyone's current opinion on the IE silicone hose kit? I like their open ended statement in the product description, "...meaning this will probably be the last hose set you will need." I'm also considering upgrading the radiator and noticed IE has an all aluminum radiator. Any advice on their products would be greatly appreciated.

[nando]

Personally, I think silicone hoses are ugly and a waste of money. The stock ones will last 25+ years. Will the silicone ones really last longer?

I don't think there's necessarily anything bad about their hose kit though. It's just the benefits aren't super clear to me. Same thing with the radiator - if your M20 is stock, a stock radiator is cheap and also lasts a really long time. There's no benefit to putting in a bigger radiator, the stock one already cools the M20 just fine. But maybe you just like the looks or idea of all aluminum, they're pretty popular.

[eco325iX]

Nando, thanks for your thoughts. I was not going for looks on the radiator or hoses. I wanted clarification if the silicone hoses actually lasted longer than the OEM rubber hoses. I was not aware that the OEM rubber hoses had a 25 year lifespan, good to know. I also figured that the IE radiator might be better that the stock one since it did not have any plastic parts, which would make it last longer as well.

[Vincenze]

An aluminum radiator actually has a shorter lifespan.
For some reason, attaching tube welds crack.

Search for "mishimoto aluminum radiator crack".

[eco325iX]

I'm guessing all these aluminum radiators (IE, Mishimoto, CSF, ECS Tuning) are made the same? And they are all prone to crack or leak?

[digger]

Aluminum radiators are not inherently going to crack. The OE rubber hoses will last pretty well. Rubber is the better material

https://www.gatesaustralia.com.au/~/media/files/gates-au/heavy-duty/hd-tech-tips/new-hose-technology-advances-cooling-system-performance.pdf

[eco325iX]

Is anyone running the Behr radiator sold at Bimmerworld (17112227281.OEM)? The description says it's a drop-in fit for the E30 88+ 325i. If so, does it work with the stock fan or is another thinner fan needed?

[nando]

pretty sure it's just a stock radiator. Nissens and Behr are the two commonly used manufacturers.

Most aluminum radiators sold are made in China. The quality can be hit or miss. Cracks around welds are probably common because they likely don't heat treat properly (or at all). When the welds cool, metal around them shrinks and this causes stress risers that later crack after many heat cycles.

[digger]

if it's a stock OEM brand then it should fit like the OE one. I'm using a OEM replacement but i don't recall if it is Nissens or Behr

[moatilliatta]

Nando, thanks for your thoughts. I was not going for looks on the radiator or hoses. I wanted clarification if the silicone hoses actually lasted longer than the OEM rubber hoses. I was not aware that the OEM rubber hoses had a 25 year lifespan, good to know. I also figured that the IE radiator might be better that the stock one since it did not have any plastic parts, which would make it last longer as well.

If anything the stiffer silicone hoses can stress the end tanks out if you don’t run stiffer engine / trans mounts.