I can't find this weird smell.

I get an intermittent smell of rubber or old air. I'll smell it for a minute or two and then it will disappear but it does eventually return. I seem to notice it when I accelerate but it definitely is not gas. The climate control is off and I just had the EVAP cleaned and we sprayed disinfectant down the cowl over the weekend, it was much better than I thought it would be. Is it possible it could be exhaust or coming from the engine compartment? I'm at a loss just looking for ideas.

I suggest that you turn the climate control to AUTO, set the temperature you want to hold in the cabin, and leave it there.

Might be an issue with the SC clutch or some such. Might be your HVAC fan. Might be puffs of stale HVAC air from your chemicals. Might be an accessory pulley is sticking and the corresponding belt is rubbing and getting very hot (look for glazed belts).

Can't tell from here - so again, I suggest you let the system air out by setting it into normal (AUTO) mode and leaving it there.

Most of the time it is set and forget on auto. I will have the other things checked you mentionted, ty.

carguy8888 wrote:

Most of the time it is set and forget on auto. I will have the other things checked you mentionted, ty.

It will be an interesting problem. Short of a heater or evaporator leak, there is nothing in the cabin's HVAC air box that would do this (emit such a smell) by itself. Except maybe the fan? My OE fan never had a problem, the original one just plain wore out. The VDO replacement reeked of ozone and was noisy. I actually got an OE fan ("Harrison Radiator" a GM company) from junkyard to replace the VDO although the VDO was/is still good, I disliked it that much.

It is not that hard to remove the fan for inspection. What you're inspecting is the motor: opening the motor case, vac out the dust from the brushes at least. If you're an electrical gearhead you could replace the brushes and resurface the commutator while you are at it. If the commutator is too badly worn you can renew it with a piece of copper pipe, a Dremel with cutoff wheel to make new landings, and some epoxy and hi temp solder (actually any rosin core lead free solder should work fine). What you do is cut new landings from the pipe, file down the old landings on the commutator, solder on the new copper bits as new landings, epoxy the voids, then file the whole commutator to a diameter the motor assembly will accept. That said, GM and Nissan used these fan motors in various cars, a good JY replacement won't be hard to get if that turns out to be the issue.

You're absolutely on the right track but I'm pretty sure I got the smell with the HVAC off so I'm assuming that would rule out the fan? Where do you get access to it?

carguy8888 wrote:

You're absolutely on the right track but I'm pretty sure I got the smell with the HVAC off so I'm assuming that would rule out the fan? Where do you get access to it?

I think that in the service manual is an explanation of when air flows through the AC. I could be wrong but I think it still allows air thru even when "off." If you have the factory manual, have a look.

The fan is under the dash on the passenger side, and removes by taking out three little mounting bolts and disconnecting the powerlead. Refer to manual for details. I think the bolts were 5 or 6 mm hex head self-tapping.

There are no instructions in the service manual for overhauling the fan, but anyone who knows in general how to overhaul an electric motor can do it. The Harrison fan motors IMHO are very nicely done, they even have rubber hum isolators and use more or less standard brushes. Practical "must replace" wear limit on those brushes is I think around 4-5 mm. The web page https://www.ebay.com/i/302411780990 has a "choose" drop down list that lets you see various standard brushes. After you disassemble your fan and measure the cross-section of the old brushes you can match up new brushes with the same cross section that look similar from the pick list. The new brushes may be too long to fit the brush guides, BUT this is not a problem since you just use a Dremel or grinder to lop off the excess and dress the contact ends ("Dress" means to shape them to fit the commutator or grind a cross hatch or ribs into the contact face).

Anyway, there is no harm in unbolting the bottom plate from the motor. That plate contains the bottom Oilite (oil soaked bronze) bearing (sleeve bushing), basically. You'll find a lot of dust in the motor, it's from the wear of the brushes. Just vacuum that dust out. If the brushes are more than say 6mm long don't bother replacing them. By the way to lubricate that Oilite bearing, just be sure it's capped on one end, fill the hole with 3-in-one, 30W motor oil, or some such (I am sure about the 3-in-one or the 30W, but I think even canola oil would work) and let it sit for 30-60 minutes (check each 15 minutes and top it up). As the oil soaks in you will notice it seeping out thru the walls of the bearing, just wipe it off.

Unlike the OE Harrison motors, the aftermarket VDO motor I had does not appear to be readily rebuildable. I mean, it *was* built in the first place ha ha but hey it just was not apparent how to do the field repairs. You can find various YouTubes of people (attempting) rebuilding fan motors. One that is similar to the one in the riv is here: https://www.youtube.com/watch?v=vuWxPwL4VgI. It is longer than it is good, but it is entertaining and has good notes - for instance to use a bit of wire to crimp the brush leads instead of just soldering them.

Great info Albert. First I want to check all of the belts and if not I will have it taken apart. I need to locate the source of the smell.

There's no rubber in the HVAC; there might be an issue with the fan motor but under the hood there is plenty of rubber to chafe and char.

Do you think something could Chase and burn intermittently? On a different note how can I tell the motor mount next to the passenger fender is good or not? How do they break? Before I am about to go searching for one I want to make sure it is dead.

Well I haven't had this happen to me in my Riviera I have had this happen to me in my CRV ; i was developing a seized caliper which was getting so hot that the rubber around the caliper piston (seal/boot) was emanating and odour. When I check the temperature of the caliper after driving down the highway I could sense that it was quite hot. After replacing the caliper this issue was solved.

dbriviera wrote:

Well I haven't had this happen to me in my Riviera I have had this happen to me in my CRV ; i was developing a seized caliper which was getting so hot that the rubber around the caliper piston (seal/boot) was emanating and odour. When I check the temperature of the caliper after driving down the highway I could sense that it was quite hot. After replacing the caliper this issue was solved.

Yes, something like this will definitely do it as well.  On my car I've not had seized calipers exactly.  I have had failed soft brake lines.  They collapse inside such that they make the calipers seize; the hoses actually have 2 layers and the inner layer just fails, trapping fluid under pressure at the caliper.

The point is - about 150,000 miles of my driving (6-7 years) is when to replace them.  I just replaced all mine last summer - should have done it earlier than I did, silly me I waited until they started failing.  Then even stupider I replaced them one by one instead of just taking a summer evening and doing them all. On calipers the wear part is actually the rubber piston rings, which you can replace "in the field" really quickly.

Thanks so much for commenting -- I had forgotten all about this problem causing that smell but indeed it does.

Albertj

Would I see any distinguishing marks on the rotors or do I have to have the calipers removed and check them. At that point I might as well buy new pads too.

carguy8888 wrote:

Would I see any distinguishing marks on the rotors or do I have to have the calipers removed and check them. At that point I might as well buy new pads too.

When I've had a hose fail, that wheel gets really hot and maybe smokes (from the brakes). Before that happens I have had the car exhibit what seems like a 'rough shift' transmission problem; the tranny will slam-shift when it gets too hot, it gets too hot from the drag on the wheels from the bad brake hoses, which is kind of like driving uphill all the time. After 5-10 miles at highway speed like that, the car gets kinda pissed... No distinctive marks or bluing of the rotors in my case.

Thankfully my trans seems to shift fine. The smell the more reminds me of old air in a tire rather than burning brakes but I'm still going to have the brakes checked.

carguy8888 wrote:

Thankfully my trans seems to shift fine. The smell the more reminds me of old air in a tire rather than burning brakes but I'm still going to have the brakes checked.

Keep after it, won't take you long to find it. If it is simply stale odors from the air intake you can mix a gallon or 2 of disinfectant-strength cleaning solution such as OdoBan, Dettol, Lysol or what have you, about a gallon of it, and pour it into the cowl vents. Follow the label directions, I think you're talking a cup or so per gallon of hot tap water. I have done that in the past to get rid of rotting pollen, a 'cat pee' smell, and stuff like that. Also it won't hurt to make sure the drain's (passenger side of the lower outside firewall, hard to find and once you find it you can't un-see it) not plugged.

You're probably right as usual Albert. I have four a few different things down the cowl. I'm not sure if it masks the smell for a a week or so and then it comes back. The weird thing is it's intermittent. I do not smell it when I get in the car and my carpet is not wet. It comes and goes seemingly when I step on the gas. I am getting a puddle at the bottom so I'm assuming my drain works. I guess I'll just keep flushing it with a disinfectant.

[quote="carguy8888"]You're probably right as usual Albert. I have four a few different things down the cowl. I'm n

There's probably something I am missing or overlooking here.

If you park outdoors near trees or plants that shed a lot of pollen, this is a seasonal thing (that is, you're disinfecting the air box every year). If not, something else is up.

No trees, car is garaged now. Buuuuut, I think it sat outside in PA most of it's life. While the car was on the lift for the passenger frame rail motor mount I had the drain checked and shot some disinfectant in there. Maybe tomorrow I will do the vents and put a bucket of water w/ Lysol down the cowl inlet again. Your knowledge base is quite incredible.

Your problem may be organic matter in the air box (pollen and other dusts). Disinfectant won't denature and flush them properly - you'll need a disinfectant combined with an enzyme based cleaner.

Any "enzyme detergent booster" will work.

Original "Odo-Ban" will work. (The current retail formulation works too but not as quickly or quite as well) The disinfectant in original odo-ban was eucalyptus oil, which didn't mess with the enzymes that I could tell.

Home centers (Lowes, HD, etc.) sell such (enzyme) cleaners in their cleaning supplies aisle. Such cleaners are sometimes sold as pet odor eliminators. Home Depot sometimes has Odo-ban, as do Walmart and sams club. There are others. Just about any enzyme-based cleaner will work for this. Do not bother with odor eliminators like Febreze. They don't fix the organic matter problem and when they wear off it stinks worse.

I have not tried it but this might be worth a look: https://www.amazon.com/ACDelco-10-8027-Vehicle-Odor-Eliminator/dp/B007Q113HK - worth looking because GM still has scientists and engineers in house who take this stuff seriously. The MSDS is http://www.weirparts.com/msds/2016/88861431.pdf. Basically it's a quat ammonium solution, which would be a pretty potent disinfectant.

The point of using an enzyme cleaner/disinfectant and not merely a disinfectant is enzyme versions tend to denature and digest the organic matter. I used Odo-Ban. So the problem here is that when quaternary ammonium is mixed with organic matter it loses its effectiveness. This makes it an ineffective disinfectant in situations where blood, urine, fecal matter or soil may be present.

I have the Otobon, how should I apply it please?

carguy8888 wrote:

I have the Otobon, how should I apply it please?

Follow the Odo-Ban label directions to make a gallon of disinfectant solution using hot tap water (I think it is something like 1 cup OdoBan to 1 gallon water); pour a quart into the cowl vents, let it drain, next day pour in another quart, let it drain, etc. You might or might not use the whole gallon.

I still wonder if there is a mechanical cause and all this disinfectant is a waste? I just don't know.

It's so difficult because it's intermittent. I believe you and one of the persons suggested the blower motor and or blower relay but I have smelled it with the units off so I'm assuming that rules it out? The brakes were checked, there is no drag. On a good note I have not smelled anything since I had someone spray disinfectant through the port on the bottom. I'm going to spray disinfectant down the vents and do the Otoban and hope for the best.