By on June 1, 2017

Mazda MX-5 Cup Coolant Neck, Image: © 2017 Bozi Tatarevic

Our race weekend at New Jersey Motorsports park was months in the making and the MX-5 Cup car known as Marylin finally felt solid. We arrived late, so the plan was to pull the car off the trailer, complete an ABS calibration, and then head back to the hotel to get a little rest before the afternoon qualifying session.

The MX-5 had other plans and started steaming from the back of the cylinder head after the ABS test.

The qualifying session was just a few hours away and the leak appeared to be coming from an unreachable spot between the cowl and transmission bellhousing. Online diagrams showed an O-ring at the joint that was leaking but the closest Mazda dealership had none in stock. If we were home in North Carolina, the move would be to go to the sole local mom-and-pop store and raid their case full of various o-rings until we found the right one, but a quick Google search showed that all we had around us were national parts chains.

These stores had no such case and their computer system showed no rear water outlet o-ring for the MX-5. Time was running out. We had to qualify. We put the car back together and sent it out on track. When it came back, the bit of steam had turned into a waterfall coming down over the bellhousing and our race weekend looked like it had come to an end.

We decided to start tearing it down and sent various people out to find universal o-rings, cleaners, and sealants. Luckily, Mazda added a removable panel in the middle of the cowl, which increased our access from about half an inch to three inches. We were able to get to the part in question after a few hours and found it had been previously installed at an angle causing the o-ring to be pinched. We had sealant but I decided to try my hand at finding a replacement o-ring. Danger Girl was on top of picking up all the parts so far and was familiar with the local parts stores, so I joined her to go searching for a better o-ring.

Mazda MX-5 Cylinder Head Cooling, Image: © 2017 Bozi Tatarevic

My first choice was NAPA as it still has some old-school service parts but it was closed for the day. We visited Advance Auto Parts and I asked the clerk behind the counter to show me their o-rings but, disappointingly, all he had to show us was a couple of boxes of injector o-rings. We decided to search on our own and found some distributor o-rings on another aisle and one appeared to be a close match to what we needed. We paid for the box and decided to head to AutoZone to see if there was something better.

MX-5 Cooling Diagram, Image: Mazda

We found the same exact boxes of imported injector and distributor o-rings there, but the fellow behind the counter was much more helpful. He was a breath of fresh air compared to the other clerk, who had as much part knowledge as a Starbucks barista. He checked his computer first. After he couldn’t find the part there, he offered to take me back to the their gasket and o-ring cabinet. We spent a few minutes looking through it but were unable to find anything that matched, and headed back to the track.

While we were riding back to the track, I reminisced about the disappearing mom-and-pop parts stores that had cases of o-rings and drawers full of bolts, which have been replaced by national chains selling discount oil and Chinese replacement parts. These stores had rows of catalogs and clerks that could tell the difference between an o-ring and a metal donut gasket. Their first move wasn’t to ask for year, make, and model but to ask what you were working on and help you find the right part.

MX-5 Cup Car Undergoing Repair, Image: © 2017 Matt Farah

I can’t help but feel partially guilty for the disappearance of these stores since most of my parts purchases happen online. Online shopping has changed the landscape for buying parts since almost everything can be found on sites like RockAuto and Amazon. I buy parts on RockAuto if I’m not in a hurry and order through Amazon Prime if I need it quickly. RockAuto usually has a choice for any given part, ranging from an economy Chinese product to a top of the line part made in the USA or Japan. The ease of clicking on a part has spoiled me and caused me to neglect the local mom-and-pop store unless I need something quickly. This usually turns out to be something like this o-ring, which usually runs for less than a dollar. A business cannot survive selling o-rings and the occasional bolt.

Bozi and Bojan repairing MX-5 Cup car, Image: © 2017 Josh Howard

All of this could have caused us to end a race that had lots riding on it but we got lucky this time. There was a distributor o-ring from a Lexus LX in the assortment that was just about the right size for our water neck. We installed it, slathered on some WaterWeld for good measure, and kept bolting the car together until just after midnight. The next morning we refilled the cooling system and prayed it would hold. The car didn’t leak and we went on to have a successful day of racing and take first place in our class. We got lucky this time and found something that worked at the chain store, but we may not be so lucky when the next o-ring or bolt fails.

[Images: Bozi Tatarevic, Mazda, Matt Farah, Josh Howard]

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21 Comments on “How a Single O-Ring Almost Ended a Race Weekend...”


  • avatar
    RetroGrouch

    For next time….
    McMaster Carr has everything and is 90 minutes from the track. Grainger locations are even closer

  • avatar
    sirwired

    Along with the revolution in cheap Chinese parts has come the easy and cheap availability of those very same parts assortments you used to rely on. While you may not have enough garage space for every bolt out there, stuff like o-rings and clamps are available cheaply. Just casually googling shows loads of inexpensive boxes of o-ring assortments. (I happen to have a small assortment from Harbor Freight, but it’s not hard to find more extensive ones.) For clamps, I have a whole wall-rack of worm clamps that can handle everything from small fuel hoses to large radiator hoses; it was $20 from AutoZone.

    Even if these assortments cost more than the $1 you would have spent at Mom-n-Pop, the time spent not driving to the parts store to pick up something stupid like that is pretty valuable too.

    (That said, I can understand you aren’t going to want to bring crates of such parts on the road to a race.)

  • avatar
    SCE to AUX

    I would have done exactly what you did, complete with all the frustrations. I might have added Lowe’s and/or Home Depot to the shopping circuit, if you have them handy.

    Like you, I prefer RockAuto or Amazon for car parts, knowing that I’m contributing to the demise of the local parts store. But the local parts store is now AAP or AZ, and besides being populated with mostly button-pushing clerks, their prices are sky-high. So for oil, filters, bulbs, and wipers, I go to Walmart.

    Glad to hear you got the racer running again.

  • avatar
    30-mile fetch

    Admirable dedication. When something so small and random can derail the entire enterprise, I’m genuinely impressed that any car completes a race and that any team sticks around long enough to make it happen.

  • avatar
    Scoutdude

    This is one of the reasons I don’t buy my auto parts at Rock Auto and especially Amazon. Fact is I can usually meet and often beat those prices locally. One of the keys is to form a relationship with the store and employees. The other key is to find the stores that focus on the wholesale market. Get known as a regular customer that buys all their stuff at the store and at least on the hard parts the prices drop, sometimes significantly. All the clerk has to do is enter one of their wholesale accounts that is cash only. Sure the receipt will say the name of that account but the prices will be 10-20% lower.

    Even without that if you find the right store the prices will still be quite reasonable, in stock or there that afternoon/next day, you don’t have to pay shipping, and you know before you leave the store that you have the correct part, at least if you actually know what the correct part is and looks like or brought the old one to compare.

    For a pricing comparison last year I wanted some XL-12 to change the fluid in my transfer case. Amazon had it on prime for $11.99 qt and they could have it to me tomorrow. At the good local Ford dealer on the other hand the over the counter price was $8.99 and they had a case on the shelf.

  • avatar
    dukeisduke

    Yes, it’s too bad that the mom-and-pop stores are going by the wayside. The two outfits I used to buy parts from in Plano, Texas (one was a one-store operation, Plano Auto Supply, and the other, Jay’s, had three locations, all in Plano), are long gone. They carried brands you knew, instead of the private label Chinese junk that AutoZone sells. O’Reilly’s seems to be a little better, though, and NAPA, too.

    Also, I pretty much stick with OEM parts now (buying them online from discount dealers when possible), after a couple of bad experiences with higher-end aftermarket parts like brake pads and rotors (Wagner and Akebono) for the F-150 I used to own.

  • avatar
    dukeisduke

    I notice that part is marked FoMoCo – a Ford part. Is it shared with some Ford product? Also, is that part of the heater plumbing? That’s what it looks like.

    • 0 avatar

      It is marked with FoMoCo like a bunch of the other parts on the car but I have not found another model that shares the housing yet. This engine and other derivatives were used in the Focus, Fusion, and others but had a different part since they were FWD. The part is the rear water outlet which leads to the house that runs under the intake manifold and terminates at the radiator.

  • avatar
    gkhize

    I’m an IT guy by trade, but a car guy in my heart. I’d much rather be wrenching on a car than sitting at the computer. Anyway, several years ago I took a second job at the local O’Reillys primarily to give me something to do in the winter evenings and to earn a little extra money for Mustang parts. What I quickly learned is that even as a shade tree mechanic I know more about cars than 90% of the other people working there. And sadly, that’s their business model. The district manger was in one day and literally said that O’Reillys wanted to be like a fast food operation. People didn’t need to know anything about cars, just how to look stuff up. On top of that, the less educated the better; the less they had to be paid. Fortunately for me the regular customers learned early on that if they asked me for something I could ask intelligent questions and find the parts they needed unlike the morons who could barely look something up on the computer. I had a farmer come in on a Saturday during harvest with a bearing out of his combine. He had to get going in the field but needed the bearing. All parts lookups were fruitless, but by simply going through the bearing inventory I found some throw-out bearing that just happened to match what he needed. I got him back in the field and he was thrilled. If I had simply followed the company approach he would have been out of luck till the implement dealer opened on Monday. It’s really a shame that the parts business has devolved into nothing much more than a drive through taco stand.

  • avatar

    Another disciple of Dorman.

    ” mom-and-pop parts stores that had cases of o-rings and drawers full of bolts”

    Frentz Hardware in Royal Oak, Michigan.

    If Durst Lumber doesn’t have it, Frentz likely will. If Frentz doesn’t have it, and it’s some kind of screw or bolt it’s Motor City Fastener. If it’s an o-ring, http://www.zatkoff.com either stocks it or they can get it.

  • avatar
    hamish42

    It could almost be worse. Our fun car is a 1967 Mini Traveler – the little woody. The most dependable parts source for us is in Webster, NY, USA, We live in Toronto Canada. The drive is 6 hours round trip, hustling. We have to put up with sociopathic border guards with anger and aggression issues, both coming and going. The parts are in US dollars – about 40% more than ours. I have to try and convince the customs agent that the $10 part in my hand is for an antique car, or pay duty on it. So call it 8 hours, 2 tanks of gas, and total aggravation for a tiny bit which has laid my car up. Don’t mention British on-line sources – they deliver by carrier pigeon. We need a North American car.

    • 0 avatar

      That sounds horrible. Can the people from NY ship to you?

      • 0 avatar
        hamish42

        Some parts, yes. But we have found that BMC in the 60s, for whatever reason, used different parts on cars which were the same make, model, and year of manufacture. For my 850 there are at least 2, and possibly 3, distributors – the electrical systems are especially bad for parts variance. Also, to my sorrow, the brakes. You have to be right there with the greasy part in your hand to compare it to the new parts. Really a drag, but we do love our little car.

  • avatar
    SoCalMikester

    might have been worth it to take the whole assembly to a ford dealer? someone there might be able to either recognize it or get a part number.

  • avatar
    -Nate

    Great story, glad to hear ot worked out in the end .

    FWIW, Dorman isn’t the same company it once was, most of their impressive parts array are made in China these days and is absolute crap .

    -Nate

  • avatar
    Erikstrawn

    I went to the local Autozone and O’Reillys last week looking for a set of brass freeze plugs for a small-block Chevy. THEY HAVE TO SPECIAL ORDER THEM! RockAuto had them to me in three days for $18.

  • avatar
    operagost

    “Their first move wasn’t to ask for year, make, and model but to ask what you were working on”

    In other words, year, make, and model. Or do you just answer, “an automobile”?

  • avatar
    pwrwrench

    “What are you working on?” “The cooling system”. Often ‘rubber’ parts, such as o-rings, are made from different material if they are used in the cooling, lubrication, or AC system. Anything might get you through a race weekend, but might not last long in regular use.
    The Mom and Pop, or Pop and Pop, or just Pop stores are going away faster than book stores. Where I live there is a hardware store that has been in business since the 1920s. I listed Pop and Pop, as it is run by the sons of the founder. I go to them first for tools, paint, plumbing, etc because they have good stuff and I want them to stay in business. We had a KMart and still have a Target, but Target closed their garden dept so less choices. Have to go 10 miles to find other stores.
    I can feel for the person with the old Mini. Many makers in that era would make production changes often without identifying them properly. I recall the frustration, when I was in the auto business of having to ask someone for a chassis or engine number to find out which variant of the part was needed.
    Also components can be replaced with ones of a different year. Ignition distributors, generators/alternators, brakes, etc can often be interchanged between models and years.
    Once, when I had 20 years experience, I was trying to find an alternator for a German car with no success. I got lucky to walk into one of the warehouses that I dealt with when the one guy that worked there, who knew what it was, came by and gave the correct part number. We joked about that for some time, “It’s Tuesday, it’s raining, it has AC. Put a different alternator on it.”
    The catalogs, which identified 3 possible alternators, were incorrect.
    In the OP case often an application of Permatex Ultra Grey silicone sealant will work. That stuff has worked near miracles for me more times than I can remember.

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