[rmnelson]

I discovered today that the auto tensioner looks extremely corroded. There are flakes of rust coming off the housing. Everything else under the hood looks fine except for a few bolts near the tensioner which show a bit of corrosion. I got out the Corrosion X and dosed the area pretty thoroughly, but I am concerned about what caused this. I have had my 2000 since November 2004, and try to be pretty careful about corrosion; this was not the first time that the Corrosion X has found its way under the hood. I've pulled the under car covers off a couple of times to clean, and this is the first I've seen anywhere. I did install the block heater when I first got the car, and it is fairly close to the tensioner, but that is the only work I have done in the area other than spraying the Corrosion X. Any comments or suggestions would be welcomed.

 

[Insightful Trekker]

Re: Corrosion on Serpentine belt Auto Tensioner

Hi rmnelson,

Ok you asked for comments.

I edited your title to accurate describe what your seeing. The timing chain is "internal" to the engine and oil bathed so I can't see how it could be corroded. As its tensioner also is. You'd need to partially disassemble the engine - the engine's timing cover (metal) to see these parts.

What you must have been trying to describe is the single drive belt and its tensioner. Commonly called a serpentine belt when more than one accessory is driven by it. In our case the water pump and A/C compressor (if equipped).

Ok, so the tensioner's shell is corroded :?: Hmmm. It sounds like small potatoes to me, nor can I think of why it appears more corroded than most any other similar metal part in the vicinity.

Reads like you did the right thing (Corrosion X).

HTH!

 

[downloader]

Corrosion happens, its normal for a car of 6 years. Depending on where your live the corrosion can be varied. Take a look at the A/C compressor, and bolts they corrode as well.

 

[rmnelson]

The corroded housing I'm looking at is described in my Helms book pg. 6-24 as a "cam chain auto-tensioner". It is just right (looking forward) and above the TWC and almost directly above the freeze plug where the block heater is installed on the back (pax side) of the engine block. It wouldn't be the first time that I misinterpreted what's what though. The Helms drawing doesn't give a lot of surrounding context and I basically just picked what looked like the housing I'm seeing covered with corrosion. What really jumped out at me is that there is no other corrosion anywhere, and pretty substantial flaking and deterioration on this housing and three or four bolts right in the immediate area. I suppose it is possible that when I installed the block heater 1.5 years ago that some of the radiator fluid splashed onto the housing, but again I am pretty careful about cleanup.

 

[Insightful Trekker]

You are correct :!:

But its still the timing chain's auto tensioners _external_ housing. Quite thick in comparison to many other parts.

I can't imagine that even if this corrosion was left untreated that it could have any consequences this century. (literally)

Posts description re-edited to try and further clarify.

Thanks for the post :!:

Sincerely,

 

[rmnelson]

I will stop worrying about it. The fact that only this one area was having a problem made me wonder if that area is working like a sacrificial anode for the engine. When I have time I will crawl under the car and see if I can hit it some more with the Corrosion X from a different angle. The bolts holding the housing to the block look like they are turning completely into lumps of rust. I thought initially about pulling the bolts off and replacing them, but decided that this would likely cause more problems than it would solve.

This also made me wonder if there are similar things going on in areas that are not as easily seen. Maybe it's time to get a garden sprayer and a gallon bucket of Corrosion X and fog the whole car. There seem to be a good number of access spots around the car, so the sprayer wand might be just the ticket. This sort of treatment is routinely done to little airplanes at relatively low cost and to apparent good effect. The bottom line is, does the aluminum construction reduce the body rust problem for those of us who live in coastal/humid/salted road areas at the expense of increased exposure of the accessories and fasteners (other than the Nacro ones) which are not aluminum?

 

[Aaron Cake]

The tensioner housing is plain old steel, unpainted and unprotected from the environment. So it will rust, no rocket science here.

If you care, use a wire brush or wheel to remove the rust, then hit it with some paint.

 

[Hollington]

Timing belt...?

Perfect time to see this post...We have a 2000 that we've just bought. It is in immaculate condition, inside and out and we're very, very happy with it. We are planning a road trip in a couple of weeks and it will be great to get to know how well it will preform. Given that we don't know a GREAT deal about maintaining cars we have been getting advice from just about everybody. It has 98,000km on it and a few people have told us that before we leave we should make sure to get the timing belt replaced. (They're suggesting all cars need this done at 100,000km before it goes and blows the engine) I haven't read anything on here about replacing the timing belt and was wondering if anyone could let us know their thoughts on this because right now we are confused..

 

[bretthans]

Hollington,

Congrats on your purchase.

I haven't read anything on here about replacing the timing belt

That's because, as John pointed out, the Insight does not have a timing belt; it has a timing chain. Please follow the maintenance schedule recommended in the Owner's Manual (if you do not have one, there is a maintenance schedule posted on this exceptional site ). You will not find any mention of the timing chain. With rare exception, the timing chain should last a very long time.