no wonder Chinese parts get bad press

[gwest]

I had the usual leaks from the oil filter housing on my 2007 Peugeot 207CC Vti 1.6 petrol, but became very disillusioned with my local PSA dealer when I was told that in order to buy the two seals that fit against the block I had to also buy the complete alloy housing, for over $600! I found very cheap kits on Aliexpress and I fitted a set in March this year. This week, five months later, I had oil on the garage floor. At first I thought it was from the front (gearbox end in French speak!) crankshaft bearing, but after cleaning things up a bit then transferred my attention to the sump. I had sealed this with a RTV silicone gasket maker, but failed to observe the instructions on the tube to only lightly tighten the joint, then leave it alone for at least an hour (at 21C, 50% relative humidity) before torquing it down completely. More cleaning and a short drive then had me looking more closely at the oil filter housing. I mean it was better than a crankshaft seal, but still pretty annoying. After removing the front bumper and moving the radiator support frame forward I was able to extract the catalytic converter, and finally, the filter housing. The main three-chambered seal was sitting flush with the surface whereas the smaller triangular seal was about 0.5mm proud. For $63 I bought the required seals (#11428643758, made in France) from a BMW dealer. I still had some new Chinese kits so I measured the width and thickness of the roughly rectangular cross section seal. The Chinese ones actually stood taller than the genuine parts (5.2-5.3mm vs 4.9) but were a bit narrower (1.8 vs 2.2). The amount of compression would be around 30% for the Chinese seals vs 25% for the BMW ones. The amount that the seals filled the groove was about 89% for the Chinese versus nearly 100% for the BMW ones. When I removed the offending seal from the housing its height had reduced to 3.8mm (the groove is about 3.7mm deep) and the width had increased to 2.32mm (the groove is nearly 3mm wide). So it had only about 4% compression, and its gland fill had reduced to 82%. And the cross-sectional area had reduced by about 8%.
Am I right in thinking that the Chinese manufacturer has made them from an unsuitable material? I used to be down on the French for making them from material that only lasted about 10 years but in comparison they did ok.

[white exec]

For something as inexpensive and low-tech as a gasket, AliExpress can be relied on to offer a good selection of tat.
Trying to get something small refunded or exchanged is often not worth the effort, so buyers don't bother, and neither do some of the vendors.

When I tried to get a quantity of 12v T10 warm white LEDs changed (they were cold blue-white in colour), I was told by the vendor that I was talking rubbish, despite having (at their request) forwarded professional-standard photo evidence to them.

Don't get me wrong, there's some useful stuff on AliExpress, but also some questionable stuff - like the 250A solid state welders that you can hold in the palm of your hand, for just €9.99. A hefty dose of common sense is needed!

For your filter gasket, just stick with original quality, likely cheaper and easier in the end.
Hylomar Blue would be a recommendation for gasket sealant.

[Nickcc102]

Looking for a childs cowboy gun on aliexpress I found one for about £5 only when I carefully read the feedback did I find that rather than the expected toy gun was in fact a metal plate with a picture of a cowboy gun.

[Dormouse]

My experience with Aliexpress has worked out at about 50/50 good and bad. Trying to return anything is a nightmare. So I have stopped using Aliexpress. I have no doubt there are good traders in there somewhere, you just have a job trying to find them.

[GiveMeABreak]

I have only just started getting a few bits from there - mostly after seeing the exact same items on the bay of evil or at 10 x the price on Amazon, but I won't get car parts from them period.

I only ever get some small non-tech stuff for general use on the following premise:
1) It is cheap tat or fake
2) It will fail imminently
3) It won't meet Western Safety Standards
4) It will likely contain hazardous chemicals or be non-fire retardant
5) It won't be what I ordered
6) Accept you will never be able to return anything, so don't buy anything expensive.

[gwest]

Given that PSA manufacture in China you would think that you might fluke finding a place that sold decent products, but like Dormouse I have had mixed success. I have had some luck with a VTi gasket set, service filters, spark plugs, PCV replacement valves) but the thermostat and rear coolant pipe I bought turned out to be for the MINI (extra outlet on thermostat and missing one on the pipe). I resold them on eBay- the actual articles looked ok. So it really is akin to gambling. One recent item that turned out ok was a HUD that plugs into 12V and relies on GPS to calculate vehicle speed (A$65). At my age trying to read the orange analog speedo display on the 207 is just too hard. But the oil filter housing seals were pushing it too far- you have no way of assessing them other than fitting them and waiting. I know PSA are not the only manufacturers to use this form of elastomer sealing for oil filter housings so I can only conclude that it must be cheaper for them to manufacture and they know that the seals will outlast the warranty period.

[GiveMeABreak]

I think you'll find that a lot of the models made in CHina are specifically for that market and are either 'cut down' but are notably different from Western models.