Won’t Be Fooled Again (Hopefully)

Everybody who does vehicle inspections has to advise the customer what needs doing right away and what can be put off for a while, and those inspections need to be thorough. At the Ford dealer, we did a 29-point inspection on every vehicle, and a mechanic with integrity will take those inspections seriously. On vehicles that obviously have to be trusted to keep people safe, these inspections are about a lot more than upsell. In some cases, if we don’t take the inspection seriously, we can miss something really important that can range from embarrassing to downright deadly.

Like This Article?
Check out related training at

Sherlock Holmes Diagnostics April 24 8:30-11:45 a.m.Sensible Diagnostics for Sensible Technicians April 25, 2-5:15 p.m.Advanced Drivability & Diagnostics: Diagnose Efficiently the First Time April 26, 8:30-11:45 a.m.

Embarrassing would be the time when a young mechanic I knew replaced a taillight fuse, checked off all the boxes on the inspection sheet and never opened the hood. When the car had to be jumped on the service lot a few hours later because he left the park lights on, it turned out that a squirrel had built a nest on top of the battery. The word “busted” comes to mind.

Another time we checked a 2010 Ford Fusion a young woman had purchased at a GM dealer, which supposedly does inspections and “certifies” all of its used cars. She heard noises under the front end during turns and went back to the GM dealer where she bought the car, only to be blown off by the service manager, who told her that they didn’t work on Fords at the GM dealer and she needed to have it checked at a Ford dealership or an independent shop. When she brought the car to us, we found that the right hand inner lower control arm bolt was totally unscrewed and was making its way out of place a little at a time. Almost half the length of the bolt was visible. And it wasn’t hard to spot. Can you imagine what kind of disaster she would have faced had that bolt come all the way out at 70 mph on a busy highway?

One of the things I preach to my students is that if something bad happens to the person driving a vehicle they inspected that can be traced to their negligence during an inspection, the potential is there for things to get really nasty. Insurance investigators love that kind of thing. Studies proved back in the 1980s that vehicles equipped with a center high mount stop lamp makes that vehicle 40 percent less likely to be rear-ended by another vehicle in stop and go traffic, thus third brake lights eventually became the order of things for cars, trucks and vans. With that as the base line, I explain that missing

something as simple as an inoperative light makes it 40 percent more likely that the person driving that car will have another vehicle crash into them from the rear.

Failing to check the final drive lubricant on a Toyota Camry or Corolla is another deadly but often-missed inspection point. That final drive isn’t lubed by the auto trans fluid on those transaxles, and if the CV axle seals are leaking so that the differential oil gets gone, those gears can (and will) lock up while driving down the highway. If somebody had you prep their vehicle for a long trip, you might find some really smelly egg all over your face the next time you hear from them.

Finding a Problem This month’s story revolves around a Dodge Dakota that had developed an oil leak between the passenger side cylinder head and the engine block, and the driver of the vehicle picked it up as an oil smell. Overhead cam engines like this one have a pressurized oil feed passing through the head gasket, thus the potential for a pressure leak exists.

Our inspection revealed oil seepage that was wet enough to make its way back to the exhaust manifold right above the header pipe. We know that can be a fire hazard, particularly in the heat-soaked subtropical summers we have here when manifold heat can burst liquid oil into flame. There was no valve cover oil leak from above the cylinder head/block joint on this first diagnosis, and the exhaust was cooking the oil before it ever dropped to the ground, thus the leak was smelled but not seen by the driver. How likely it was to catch fire isn’t as pertinent as what could happen if it did.

This oil leak wouldn’t be a cheap fix either. You don’t just yank the heads off a Dodge 3.7L, pop some new gaskets in place and then sew everything back up. Thanks to the wonderful world of overhead chain-driven cams, this baby would be a big-ticket fix. The timing chain set alone was almost $500. The green light came, the parts were ordered, and Bobby plowed into the job with zeal. He had the timing cover, intake and valve covers off pretty quickly, and I explained that it’s sensible to pop those roller rocker arms out of there so the cams won’t be hard to turn and the valves will all be closed. He did pop them out of both heads when he replaced the valve stem seals. He disassembled the timing chains and took the heads off with those rockers in place, cleaned everything and started his reassembly. After I had told him the rocker arms needed to be left on the bench while he was installing the heads and timing the engine, I later noticed that he had left the rocker arms out of the driver side head but had installed them in the passenger side head, which was an idea.

When he torqued the head, it turned out that since the rocker arms were in place, there were valves touching pistons, and when he finished assembling everything, the engine started, ran for about 20 seconds, started making a noise in the timing chain area, and then died, a set of circumstances that gives just about any mechanic an instant sick feeling. If that wasn’t enough, when we checked the oil, coolant had made its way into the crankcase somehow, and so the head needed to come back off. More about that in a minute.

Finding Other Things
Some things we find in the course of normal service tend to give us pause and make us wonder what the heck they mean. For example, one customer brought a 2002 Chevy Silverado to us for an oil change, a U-Joint and some brake work. That particular engine had an oil drain plug with a magnet on the tip of it, and when we removed the drain plug, a valve keeper was clinging to the magnet. What, exactly should we do with this information? Did it pick up a valve keeper from the previous oil changer’s bench that he or she didn’t spot when the plug was reinstalled? The keeper looked a bit small to have come from that 5.3L, so we told her about it and continued with business as usual.

Then there was my aunt’s 1992 Crown Victoria, which had developed a roaring road noise that changed from silent to louder during swerving maneuvers. I swore it was an axle bearing until we jerked the differential cover and pulled the axles; both bearings were pristine, as were the axle surfaces. That one turned out to be a bad left front tire – you could spin it and see the tread wobble. Of course, we didn’t look in the front until the ChassisEar^® alerted us to the fact that there was no unusual noise in the rear. Who knows why the rumble from a bad left front tire sounded so much like it was coming from the rear? It was a great experience for the guys who saw that happen. Early on, we did find a rough rear U-Joint on that one and we replaced it, but we knew going in that what we were hearing wasn’t a U-Joint.Speaking of noises that telegraph, we burned some time chasing an annoying exhaust leak noise on a 2008 Altima that sounded like it was coming from up in the passenger side intake manifold area. The exhaust is a long way from the place where we were picking up the sound (we used a stethoscope with its probe removed as a listening pipe). Melissa decided to remove the exhaust heat shield, and she managed to short the alternator out and blow the main fuse at the battery ($26 from Nissan). But she did use the stethoscope to find that the catalyst was leaking from a crack on the top rear of the cat’s case. The heat shield had funneled that exhaust noise up under the big cast aluminum brace that covers the passenger side of the engine to the intake area, and it had projected the noise to that thus our initial belief that the noise was

originating in that area. A replacement cat alone would cost more than you’d pay for some used cars here in South Alabama, and so we removed the cat/manifold assembly and carried it to the welding department, where they did a factory-perfect job of sealing the crack.

One of the more interesting quickies we dealt with about this time was a 2002 Mazda 626 that had a low brake pedal and fluid that quite literally looked like V8 vegetable juice. We found powder-fine red putty in the reservoir the same color as the fluid - no flakes of rust to cut rubber seals, and since DOT 3 is hygroscopic (it absorbs water), I wondered if a misguided somebody had poured water into the master cylinder at some point (although I couldn’t say for sure). But when we replaced the master cylinder and flushed the brakes by pumping about a gallon of fluid through there, it stopped well and the pedal was high and firm. If that one had been equipped with ABS, it would have been more troubling, but as it was, the brakes worked fine.

Off With its Head
Bobby got the head off the Dodge to find that he had bent three intake valves, and so I ordered three brand new $16 valves, lapped them in, checked the seats with Prussian Blue, put the head back on with another new gasket and sewed it all back up. The coolant had made its way into the crankcase because one of those intake valves was touching a piston and prevented proper torque on the gasket. I also preach about blowing the liquid out of all the cylinder head bolt holes before reassembly.

When we started the Dodge again with new oil and new coolant, that doggone passenger side timing chain was still throwing a rattling fit. We yanked the cover off and started the engine with the chains exposed, and the tensioner was bouncing (its ratchet mechanism can’t take the pressure alone) like there was no oil feeding it. When Bobby took that tensioner back off, a thin piece of foil fell from the back side of the tensioner and the mystery was solved. Apparently the foil had fallen from the other two tensioners on the first install. Problem was, the new tensioner had held onto its foil too long and had been damaged by the trauma; it acted the

same way even when reinstalled without the foil and fed with oil, so we reinstalled the original tensioner for that side and things got nice and quiet.

We ran the 3.7L for a while and then noticed we still had an oil leak on that side, so we poured in some dye and re-drove it. We found that the passenger side valve cover gasket – brand new – was leaking between the gasket and the head. With the valve cover once again removed, I noticed the sealing surface was clean and shiny and the gasket wasn’t damaged, but another new valve cover gasket did the trick.

Bobby now knows 3.7L Dodge timing chains inside out, and I imagine the next time he does one he’ll beat book time hands down. That’s one of the benefits of having to do and then re-do a job where mistakes were made. He won’t make those same mistakes again.