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The perils of automotive diagnostics and repair

Monday, January 1, 2018 - 09:00
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I have a 1989 Ford Bronco that was donated because the owner believed the head gasket was blown, but it was running crappy and puking coolant out the neck because it was a 5.8L, and he had wired it up using an old 5.0L firing order. When we wired it up with the right firing order, all the filler neck geysers went away.

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A few years ago, we checked a 2.4L Dodge Stratus with a horrible oil leak that a shop had pegged as a rear main seal (how many offhand rear main seal diagnoses have we seen?) and used dye to find it coming from under the corner of the head.

Those of us who teach for a living know from experience that people who already believe they have all the facts are kind of difficult to convince otherwise.

2011 Chevy HHR 2.2L Ecotec

Bearing bad news

The owner of a 2011 Chevy HHR, 22L Ecotec with 123,598 miles had spent some time and money doing his own offhand diagnosis trying to get it started – he had checked the fuel pressure with a rented gauge, replaced the fuel pump and fiddled around some with a scan tool before realizing that he was in over his head. The HHR been sitting for a few months when it came in on a trailer. They had determined that it had to be something simple and were hoping we could get it going for just a few bucks. Somebody had postulated that it might have a bad crank sensor, and they brought it to us with the hope that we’d find out it was something simple. Well, it wasn’t. This one spun with very uneven compression, and when we removed the valve cover, we found some broken roller rockers, which typically means valves had contacted pistons, usually the result of timing component failure. But the timing chain was nice and tight, and looking down into the chain area I didn’t see any looseness or shattered sliders. Could it have been over-revved enough to float a valve? We didn’t do exploratory surgery, but we sold them on the idea of replacing the bad engine with a good used one.

When we pulled the valve cover on the HHR, we found several broken roller rockers. Something catastrophic happened here, so we decided to stuff a used engine in it.

The salvage yard sent an engine for that one with a few minor differences – the fuel rail had a different shape, along with a couple milder changes. When we were done, that one ran like a top and when we fixed an A/C leak and juiced up the icebox, it even had cold air.

The Expedition and the Crown Vic

A very regular customer brought her 2001 Expedition to us with a nasty coolant leak – this one’s a Triton and they tend to protect themselves from engine damage, but she just kept driving it. The water pipe that travels through the valley under the intake had rusted through and was dumping water almost as fast as you could pour it in. Initially we just removed the intake manifold, cut the rusted-through portion of that pipe out and replaced it with a hose and some clamps along with a new intake, but when we filled it with coolant, put a new thermostat in it and started warming it up, the warming never stopped – pressure was building very rapidly throughout the system and it was evident that this one had indeed blown a gasket.        

She’s a hands-on shopper, so she did her own search for a replacement engine at a price she liked, found one somewhere in Florida, and had it delivered to the shop. It had the heat pucks in some of the expansion plugs and so I knew it came from a reasonably savvy salvage yard. I crossed my fingers, hoping they didn’t turn the engine backwards while removing the torque converter bolts! Sometimes that flips one out of time.

Since I had people doing transmissions this time around, we went ahead and jerked the transmission out first, then I had another guy remove the original engine, and we carried it on the hoist over to the area where we do component swaps.  One of the first things we noticed was the narrow pulleys on the replacement engine – apparently this one had come from a Crown Victoria or a Town Car, but I couldn’t be sure. Oddly enough, a power steering pump came with the replacement engine, and so we took that narrow pulley and put it on the Expedition’s PS pump. We also replaced the idler and the belt tensioner, because those wide ones wouldn’t work on the replacement engine’s timing cover – and we weren’t about to swap out the timing cover if we could get out of it.

Initially, the guy who put the engine in the Expedition had put the generator wire on the top post at the solenoid, and that kept the starter energized when the generator was trying to work. The starter was a casualty in this case, but it’s an easy mistake for a beginner to make. The bottom photo shows the naked grooves in the generator pulley – the A/C compressor had the same issue, but we swapped out the power steering pump pulley to have the right one.

There were some other minor differences, but at the end, that engine was sitting in the frame with a new belt and everything plugged in, and the transmission was reinstalled – having drained the transmission and replaced the filter, we needed to start it up to get all the fluid back in the gearbox. We started with five quarts and hit the key.

When we started the engine to finish refilling the trans, we noticed that it had a large vacuum leak, and we also heard strange noises and smelled something burning – never a good sign, and it wasn’t the oil smoke from exhaust manifold handprints, either. As it turned out, the guy who replaced the engine did everything right except that he made one very easy mistake. He connected the alternator charge wire at the starter relay to the wrong post, which delivered alternator output current to the starter solenoid circuit while the engine was running, and that kept the starter energized, which destroyed the starter. Thankfully, it didn’t destroy anything else. But with that heavy rubber sleeve on the wires leaving the solenoid, it was easy to make that mistake if you weren’t ultra-familiar with the wiring.

This was another easy mistake to make – put a bolt that’s just a little too long in one of these and you’ve ruined a gas tank. We used the bolts and the gasket that came with the new tank, and so this leak really surprised us – even more so when we found out the new pump was faulty.

The 2003 Crown Vic ran out of gas while the gauge was reading a half tank. We replaced the sending unit with a new one from Carquest, and the guy who did the job used one bolt that was a bit too long when installing the pump, and punctured the gas tank. We got a new replacement tank, but after it was filled with gas, the leak was worse than ever. But that leak wasn’t around the gasket, it was around the plastic grommet where the wires pass through the mounting plate – I have not seen that before. Anyway, all’s well that ends well, and there was no fire. Only a bit of wasted gas.

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