[MBGraham]

Our 98 E320 seems to have intermittent tire leaks. Every now and then one or two of the tires lose pressure. It's my wife's car, so she does not always notice this!

We have taken car in to have specific tires checked. They never find leaks. Could be the rims leaking so they probably put some gunk on rim and re-inflate. But a couple of months later, same thing.

Last night, one tire was down very low (maybe 10lb) and another low (20lb). I pumped them up to about 35psi. Then checked again this morning and there was no noticeable loss of pressure.

I was thinking of swapping on the spare rime (it has never been used) and getting the tires swapped. It looks a bit TOO new!

Need new tires soon anyway, so going to drive car myself for a while and monitor pressures more closely. I don't really want to put new tires on bad rims.

Question: Have others had same experience with slow leaks, likely from rims? If so, what have you done to correct problem?

 

[Kajtek1]

I am having such issues on chromed rims.
Unfortunately chroming is not something done in Germany and done by US dealers it comes with headaches.
Tire shops have special dope to solve that.
If you want to play with it, take the wheel off, pump it to max tire rating and spray soapy water around the rim on both sides.

 

[SkippyJasper]

Word of caution on your spare tire if it is original. A new looking 19 year old tire is still a very old tire and shouldn't be used on the roadways.
I had a similar epiphany when I replaced tires on my '98 and bought 4 Michelins and an off brand for the spare.

Could be the valve stems or the cores if original.

Skippy

 

[nelbur]

You can find the leak by spraying a soapy cleaner all over the tire, including the bead area and the tire valve. Check it over in about ten minutes. A leak will be blowing white bubbles at the leak site. No luck. Move the car enough to spray the portion that was on the ground. You should find the leak.

 

[MBGraham]

The tire dealer has better methods of finding leaks, but as I mentioned did not find any. Presumably it is the rim that leaks, but once fully inflated it must re-seal. Then after driving for a month it all of a sudden leaks down again. I will have to talk to one of the better shops and see what they suggest before installing new tires on these rims. Presumably some of Kajtek's dope!

Was thinking about tire pressure sensors so my wife doesn't drive car with low tire pressure. But not sure if the aftermarket sets are any good.

I do have a second set of rims. But they are 17", staggered and have a little curb rash. Currently have snow tires on them. Could use them, I guess, but would prefer to put new tires on original rims.

 

[Kajtek1]

Add-on TPMS work well, but they are design for metal steams.
I bought a set for my motorhome like 15 years ago and off-season had it on my car.
Turn out even the sensor was only 1 oz, the centrifugal force was flexing rubber steam and the valve was rubbing the wheel paint.
When you change the tires, you can opt for installing TPMS that mount inside the rim.

 

[GTO71]

Could be a hairline crack in the rim that remains sealed unless direct pressure is applied to the "sweet" spot and open the hairline crack a bit too let out the air.

I had this issue on my wife's W204 it was a pain, same issues as you described.

 

[nelbur]

The tire dealer has better methods of finding leaks, but as I mentioned did not find any. Presumably it is the rim that leaks, but once fully inflated it must re-seal. Then after driving for a month it all of a sudden leaks down again.

The tire shops I am familiar with drop the tire into some sort of water bath and look for bubbles. Only big leaks are visible by this method, due in part to a lack of patience of the tire tech. The "coat the tire and rim with detergent concentrate", is a far better method because it will accumulate bubbles over time in one spot.

I am also skeptical that the leak comes and goes. Slow leaks just seem that way. You might benefit by pumping the pressure up temporarily to about 45 pounds and then look for the leak. I do not advocate running on the road at these pressures, as when I have tried it the handling was a bit squirrelly.

 

[pt_700]

i had similar symptoms on my car, traced to a slow leak from the valve stem. i wasn't able cure by tightening or replacing the core.

took it to a tire shop to replace the entire stem and they found corrosion on the rim. i'm guessing this eventually worked it's way into the valve, keeping it from sealing.

 

[MBGraham]

Could be a hairline crack in the rim that remains sealed unless direct pressure is applied to the "sweet" spot and open the hairline crack a bit too let out the air.

I had this issue on my wife's W204 it was a pain, same issues as you described.

It could be something like that. Alloys in Canada are known to corrode due to salt used on roads in winter. Many now put steel rims on in winter. We now have a separate set of winter alloys, but the originals had already seen their fair share of salt.

For now, I am driving the car and will monitor pressure. So far no noticeable loss after 2 days.

No TPMS required or even common in Canada. Aftermarket ones sold have mixed reviews. Some are aluminum and corrode onto the brass stems. Probably won't go that way.

Slime is another option. Again mixed reviews. (Our 2014 GLK came with a Slime type kit instead of a spare!) May be worth a try if problem persists seeing tires are near end of life anyway.

 

[Kajtek1]

Slime is excelent on even moderate leaks due the tire puncture.
Love it on bicycles and wheelbarrows, but if you have leak around the rim = no help.
Buy your wife "tire checker"

 

[MBGraham]

Slime is excelent on even moderate leaks due the tire puncture.
Love it on bicycles and wheelbarrows, but if you have leak around the rim = no help.

Are you saying my GLK is no better than a wheelbarrow?? Seriously, I think you have a good point. Slime gets thrown to outside of tire, so not much good for beads & sidewalls. Mind you if you use Google, many say it worked for them.

Current solution, is I drive the E320 and wife drives the W123. No air leakage since I have been driving it :wink

 

[jll13]

Same issue on my w124 wagon, even with new tires and valves.
Recommended pressure should be 2.2 to 2.3 bars, and from time to time, one of the wheels records 1.2, slowly leaking from the previous pressure control. But, never below! That is very strange indeed. As the tires where new, I also suspect a rim issue on that wheel. I intend to monitor that by myself when the wagon will be on the priority list. So, for the time being, I go and chek pressure quite often, and updgrade that wheel that often.

Major question for me is: why the tire does not go totally flat?

Will follow that thread.

Jean-Louis

 

[e-420]

alloy or especially chromed rims are known to develop leaks around the bead seal. with alloy rims, usually caused by corrosion from road salt creating a rough surface in the bead seating area. On chromed rims, from chrome flaking off in the bead sealing area due to poor process control during plating.

Note, factory chromed rims seldom exhibit this issue, but is much more common with factory rims that have been chromed by a third party, or aftermarket chromed rims.

In both cases there are two options.

1) replace the rim
2) take the tire off the rim, completely clean the bead area with a good rotary wire brush, then filling any affected areas with a sealant. 24 hour cure of jb weld applied very thinly then wet sanded to smooth after it has set a few days seems to work very well and last a long time. all you want to do is fill any voids, not build up anything. you can apply the jb weld with a brush to get it applied in a thin enough layer.


The goop that tire shops apply to the bead is IMHO a temporary solution at best.

Given how long it often takes to drop pressure with this kind of leak, one must look very carefully for bubbles around the bead area to see the leak.

 

[Kajtek1]

There is no factory chromed rims on MB.
I think MB people are smart enough to avoid it.
Over the years I bought several chromed wheels and I heard that back in 1990's lot of customers liked them, so lot of US dealers send MB wheels to chrome shops.
All of them had a problem sooner or later.
The only chrome that is not giving big problem is on Lorinser wheels, what I believe is factory chrome. Not bulletproof, but my wheels might be over 20 years old and still look good, holding the air .

 

[andrewSF]

I had a slow leak issue on my original tires on my 1999 E320. Back in, around 2006, I blew out one of my original factory tires. I then took the same model, original factory tire from the spare tire and placed it on the wheel that had the blown tire. I drove with that tire and the other 3 original tires until around 2015. All during this time, that tire had a slow leak where I would lose maybe 1 lb psi every 2 weeks or so. None of the other tires had the same symptoms. In my case, the leak rate was constant. I took the tire to both the dealer and a tire shop and neither one could find the leak.

I've been driving on four new Bridgestone (Costco) tires for the last couple of years. On these tires, I would lose maybe 1 psi every 4 to 6 weeks, which I would consider normal--or at least, not alarming.

BTW, I found that rubber tires apparently have a lifespan, even if you don't drive on them. I believe 6 to 8 years is the life cycle, before replacement is recommended. Some people push this though.

 

[Kajtek1]

FIY most of manufacturers recommend replacing the 6 years old tire due the age.
I was driving on older tires, but they have been garaged most of its life and often inspection never discover a crack on them.
Constant small leak is mostly due the valve.
I just have it on new Ford.
The TPMS will loose 10-15 psi every 2 weeks.
The other 5 tires still have factory air from February.
I sprayed the valve and it takes some waiting for bubble to show, so quick look would not notice it.

 

[MBGraham]

Maybe we should go back to tubes!

 

[e-420]

There is no factory chromed rims on MB.
I think MB people are smart enough to avoid it.
Over the years I bought several chromed wheels and I heard that back in 1990's lot of customers liked them, so lot of US dealers send MB wheels to chrome shops.
All of them had a problem sooner or later.
The only chrome that is not giving big problem is on Lorinser wheels, what I believe is factory chrome. Not bulletproof, but my wheels might be over 20 years old and still look good, holding the air .

a properly chromed wheel should not develop leaks. that said, lots of aftermarket chrome jobs are not done properly.

I have had mutiple cars with factory chromed wheels and after 15-20 years or so on each of them, none ever developed leaks. My SL500 has the factory rims that were chromed by the dealer. So far after 20 years they are not leaking, but again the quality makes a big difference. Done properly they lay down a layer of copper over the base metal, then nickel then chrome on top of it.

I had a set of aftermarket chromed rims on another car that after about 6 years had two that started leaking and taking them apart, chrome was flaking off in the bead area causing leaks.

Another car had aftermarket chrome rims that were fine after 15 years.
So.... it depends a great deal on the quality of the chrome job.

Factory or aftermarket alloy wheels can also suffer from corrosion and pitting from moisture in the bead area giving similar problems.

 

[Kajtek1]

Chroming is a skill and not easy one.
Few years ago I bought "new" AMG monoblocks very cheap for less than the new tires on them were worth.
Why? The guy who was hobbying with MB had new rims chromed and put high performance tires on them, but then got busy with other jobs and wheels sit in garage for months. The chrome start peeling on them before they were ever used.
I bought the wheels for value of tires and research rechroming. The only company in So California could do that, but for cost higher than new AMG wheels.
I used the tires and putting my son's car on ebay, put those wheels on it.
That E300DT with 260k miles sold for $3500.