TL:DR – crank but no start, no DTCs, it was the fuel pump.

So, I’ve got a 2006 Infiniti G35 Sedan, with a VQ35DE rev-up engine that randomly died while driving one day. There were no diagnostic trouble codes (DTCs), nothing was obviously broken, belts were intact, no fluid puddles, no strange smells, but I couldn’t get the engine running again so I had it towed to my house.

The only notable information I got out of my OBD scanner was that the battery voltage was too low – under 11V while just sitting there. This led me to believe that the alternator had failed, causing the battery to drain, eventually so much that it couldn’t keep the coil packs firing. Given that there were no codes, no engine stumbling, really no warning at all that something was wrong, this seemed to make sense to me.

Given my (wrong) diagnosis, I went ahead and replaced the alternator and belts since I had to pull the tensioner out to clear a path for the alternator. The battery was manufactured in 2016, so I replaced that too, just in case. All that, and the engine still wouldn’t start. Still no DTCs. Damn.

Everyone knows you need fuel, air, and spark to run an engine. If I sprayed a little shot of starter fluid into the intake, the engine would run until that burned off. That checked air and spark off the list, and I checked for fuel flow by taking the fuel line off the injector rail and letting fuel flow into a catch can. I tried cranking the engine then checked the catch can, which had fuel in it. OK, so that leaves me with fuel, air, and spark, no DTCs, and an engine that wouldn’t start. Rad. Time to trawl forums.

Apparently this behavior is a relatively common occurrence in the G35 and 350Z. Common root causes include bad crankshaft position sensor (prevents spark, not my issue), immobilizer issues due to a bad key (also not my issue, the red security light wasn’t lit), and bad camshaft position sensors (prevent injectors from firing). That sounded a lot like the behavior I was experiencing, but in pretty much every forum post that I saw, they talked about seeing DTCs indicating that these sensors had failed. The ECM was still definitely working because I could see data over the OBD2 link, and disconnecting the above sensors did cause codes to be thrown. Fuck it, sensors are $40 each, and not that terrible to replace, lets just try it. Aaaaand nothing. Same exact behavior.

At this point I’m pretty sure its a fuel issue. I pulled the rear seat out, pulled the pump, and checked the filter. I could hear the pump prime when I went to accessory mode, and when I was cranking the engine. Repeatedly cycling the key to prime the fuel system multiple times would get the engine to briefly fire before dying again. I was convinced it was an injector wiring issue at this point.

A friend of mine agreed to come help troubleshoot – an extra set of eyes ears and hands to watch pumps and injectors while the other person is turning the engine over was super helpful. They also brought a fuel pressure gauge; just because I could flow gas into a catch can didn’t mean I had sufficient pressure to feed the engine. We hooked up the pressure gauge, turned the engine over, and saw… 4 psi. Fuel pump it is. We swapped it out for a new one, and the engine fired on the first try.

I’m glad it was something easy, but damn, this really eluded me. I was used to modern high-pressure direct-injection when I worked at Ford, so I was sure a bum pump and low pressure would throw a code. Guess I was wrong!

Since it’s 2021 and forums aren’t really a thing anymore, I decided to write this up for the next poor bastard with a VQ engine that won’t start.

With the cooling system disassembled and flushed, the only thing standing between me and reassembly was some RTV and corrosion byproducts on the sealing surfaces between the block and water pump & thermostat. A bit of scraping and buffing with a plastic putty knife and Scotch Brite, and I was set to install my new parts.

new water pump, thermostat, and hoses

With a new thermostat, water pump, coolant expansion tank, and radiator hoses installed, I was ready to fill and bleed the loop, following the Forum-Approved method of setting the heater to max temp + low fan to allow the heater core to fill and bleed as well.

Having solved my coolant leak, I moved onto diagnosing the main issues of the car; It drove like crap. When I test drove it, the owner told me that one of the rear springs was snapped, but a new set of springs were included, and sat in the trunk of the car. Upon inspection, I discovered that both of the rear springs were indeed snapped, due to the design of the lower suspension arm trapping grit and water in the spring groove. Replacing the springs is very easy in the rear of the car; you simply press down on the trailing arm with your foot and pull the spring out with your hands. Unfortunately, that was the least of my problems.

I had discovered that my rear subframe, the part that holds the differential to the body, had torn out three of its four mounts. That meant I’d need to remove every part of the car between the rear bumper and the transmission to patch the sheet metal. Somehow this was a known issue, unique to the 1999 323i, that I had missed before buying the car. Forums argued that it should’ve been a recall, with BMW replacing the rear floor of the car, but I was well out of that service window, being a 19-year-old car. This is where the private sector took over; there were many kits available to reinforce and patch the failure points. Some merely covered the surface where the subframe mounted, but others sought to fix the problem and ensure it never happens again by also covering a significant area around each mount point. I bought one of the larger, more robust kits, from an eBay seller in Russia. (I’d later learn that it was a knockoff of a different kit)

In order to remove the subframe and repair the mounting points, I would need to remove the exhaust, driveshaft, subframe, fuel tank,  and brake lines, roughly in that order. Being the dead of winter (2016) in an unheated garage, I had limited time to work.

Up first was the exhaust. The middle supports were first, and were relatively easy, since they were vertical studs an had limited access to water splashes. The muffler at the rear of the exhaust pipe was held on by four nuts right at the bumper. At the front of the exhaust pipe, it connected to the exhaust manifold of the engine with four copper nuts on four stainless steel studs clamping two flanges together. These would prove to be some of the toughest connections to break on the entire car. One nut was completely gone, one I pried off with vise grips, one I hammered a 14mm socket onto, and the other was still the specified 15mm. While I covered that in one sentence, I want to emphasize that it took many hours of torching and prying at the fasteners in a 14°F garage. Somehow the gasket between the manifold and the rest of the exhaust pipe had fused the pieces together. Freeing the exhaust tips and using the length of the system as a lever to break the exhaust free wasn’t an option because I was worried I’d crack the manifolds. I resorted to chipping out as much of the gasket as I could with a thin putty knife, and then cutting and drilling out the studs holding the exhaust flanges together. I consumed a non-trivial number of drill bits in destroying those studs.

yes, that is three 15mm nuts

With the exhaust out, the driveshaft was exposed. Seven bolts total held it to the transmission and differential, with an additional pair of studs holding a central support bearing. Next up were the hydraulic brake lines, and the parking brake cables. They hydraulic brakes were a piece of cake since all the fittings were brass, you could twist and they’d either come apart or get shredded. The parking brake cables were a bit of a hassle, since the parking brake components were mostly fused into one solid block of iron oxide. The brake lines themselves are included in this carnage, the rear right snapping as I bent it away from the caliper, the rear left holding on by a thread.

Once these were disconnected, I could drop the subframe freely. Three nuts later (the 4th was completely torn from the sheet metal) and the subframe, diff, and half shafts could be lowered from the car, and pulled aside. I simply lifted the assembly from the diff, and let it fall from the mounts. The fuel tank was more of a challenge since its an irregular shape, and had many rubber hoses that had fused to the barb fittings over its 210k Mile life. A bit of prying and a sheet of plywood later, and the fuel tank (and evap system) were removed, finally exposing all the mounting points of the subframe.

Now is about the time when I realized why an $800 price tag might’ve been too much.

Diagnosing the puddle of coolant started me on a trend of scouring BMW forums for information, how-to’s, and general information about my new project. Luckily (???) coolant leaks are fairly common, and easy to repair on the e46. The major components, thermostat, coolant expansion tank, and water pump, are all plastic, and are prone to cracking as they age. I suspect all of those components were factory originals which a previous owner tried to leak-proof with RTV and silicone caulk instead of repairing. A quick check for dripping coolant confirmed that one of the usual suspects, the water pump, was the leaker. Forum posts recommended replacing the whole cooling system at once to minimize coolant losses, so off I went to the land of aftermarket German car parts to order a new water pump, thermostat, expansion tank, radiator hoses, FEAD (Front Engine Accessory Drive) belt, and miscellaneous O-rings, hardware & sensors.

With many car projects, step 0 is to get it on jack stands and remove the wheels. I have no idea when the last time the wheels came off of this car, but it must’ve been years before I got it. I was attempting to break the lug bolts free with the longest wrench I had; the BMW factory tire iron. It wasn’t long enough that I could just stand on the end of it to break the bolts loose, so I had resorted to stomping on it as hard as I could. This would be the first (but not last) time I’d learn that the right tool makes all the difference; on one bolt I stomped, and my foot slipped between the tire iron and the wheel, very nearly breaking my ankle, and leaving me with a scar on my right ankle. Some time and swearing later, I drove to Harbor Freight and got a 25″ long 1/2″ drive breaker bar.

First up was removing the main fan, draining the coolant loop, and removing the radiator hoses and expansion tank.  Up next was removing the AC belt and main FEAD belt. This is where things started going as well as one could expect when working on a car with 210k miles. Both belts had different tensioners, and different methods for releasing the tension to remove the belt. The AC belt needed a 6mm hex (on a socket wrench). In and of itself, that isn’t a problem, the problem was when I knocked the hex adapter off the ratchet and it fell into the gap between the radiator and the front bumper. Knocking on the assembly, you could hear the bit rattling around but I couldn’t see it, I couldn’t reach my hand into the gap far enough to grab it, and I didn’t have the right size cheater pipe to use with a normal 6mm allen key. Seeing that all the hardware stores were closed and I wasn’t ready to stop working, that left removing the bumper and all the electronics in it.

With the recovered adapter, removing the AC belt was as easy as leaning on a socket wrench. The FEAD belt was more challenging since no diagram I found clearly illustrated what bolt you needed to lean on to release tension. I chose one that seemed right, pulled, tired the belt, pulled harder, and then heard a snap. It turns out that I picked the wrong bolt, and snapped my first bolt. This bolt, as far as I knew, was in the engine block and I had put an early end to my project. Before stopping for the day, I continued by removing the thermostat and the water pump, which is where the leak originated at a patched seal.

Upon further review, I learned that the broken tensioner bolt was not in the block, but was in the oil filter housing, which was in theory removable. Removing the oil filter housing would also require removing the alternator, and nudging the power steering pump and reservoir out of the way to get access to the six bolts holding it to the block.

A few attempts with an extractor set later, I managed to successfully get the bolt out with no damage to the base metal. I opted to replace the black gasket you can see in the above picture, as it’s a common oil leak spot.

Now the only thing left to remove from the engine before rebuilding the coolant system was the coolant itself. The engine block bleed plug was in a hard-to-reach position, and coupled with whatever corrosion was on the bolt, I couldn’t break it loose, and didn’t want to throw a breaker bar on it for fear of breaking it. Instead, I opted to use an air compressor to blow bursts of air through the block in an effort to clear pooled coolant out of the water jacket with moderate success.

By this point, September (2016) was drawing to a close, and I still hadn’t found a suitable car for the right price. One car that really caught my attention was a mid ‘90s BMW 525i, but it was located about 2 hours north of my house. The price was right, but I thought the pictures on the craigslist posting didn’t tell the whole tale. Since I didn’t want to drag myself and a friend (assuming I’d buy the car) that far north for nothing, I contacted the seller asking for the status and pictures of the underbody, shock towers, and a few other failure-prone areas.

Ultimately that 525i wouldn’t be the car; it was too far away and there were too many questions about its condition. It did set me on the path to my eventual car of choice though. A 5-series was too heavy and had too many comfort features that I didn’t want. A 3-series would be a good candidate, since they were reasonably well-powered, rear wheel drive, and there are tons of cheap parts floating around since they sold a shitload of the various 3-series’ over the last 20 years. Luckily, I spotted a 1999 BMW 323i on craigslist with an asking price of $1100, and located just two towns over from me. I had a friend give me a ride over to get a second set of eyes on the car, and because I had a good feeling that I’d end up driving that car home.

We pull up to the address we agreed to meet at and it looks like an abandoned business, but sure enough, there is a white BMW sitting out front and another car whose driver looks like they’re waiting for someone. We introduce ourselves to the seller, and he starts showing me the car, starting it up, explaining some of its known faults, the usual stuff associated with a craigslist transaction. Highlights of his explanation included at least one snapped rear spring, the instrument cluster was non-functional, and the car included a set of 10-point star chrome rims. Additionally, I found ~10 diagnostic trouble codes (DTCs) when I scanned the car. Nevertheless, the car started and ran just fine, and after taking it for a quick test drive up and down the block, I agreed to buy it. He was asking $1100, I offered $900, and since I explained that I was going to fix it up and race it he counter-offered $800 on the condition that I send him a picture of it on track within a year.

We do up the paperwork, I hand him a wad of twenties, and he hands me the keys on a ring with what appeared to be two house keys and a rape whistle (never used, according to the owner). Shortly after, we part ways, and I have my friend follow me home just to make sure my new ride didn’t leave me stranded somewhere on 12 Mile Road. Gordan following me served multiple purposes: first was to help if I broke down, second was to flash his lights at me if I started speeding (since the instrument cluster was dead), and third was to obscure my lack of plates from any police we might pass. That third point was more for convenience than anything, since the signed vehicle title serves as a temporary registration, and if you’re familiar with the area, you’ll know that cars driving around without plates is nothing unusual. We make it to my driveway without any trouble, where I park, thank Gordan for his help, and send him on his way before going back out to the Bimmer to see just what I had gotten myself into. It turns out that it was more than I bargained for; there was already a growing puddle of coolant in my driveway. “Hmm, weird, I don’t remember any coolant puddles on the ground when we went to pick it up, I’m sure its nothing”

Nope. wrong again, it was definitely something.

Here’s a short overview of the car after I picked it up:

slight rust on sheet metal edges the driver’s seat and steering wheel were severely worn aside from a few tire marks, the rear seat was in good shape Dinan tuned? (yes, I called them with the VIN and they confirmed it had their relfash) Dinan cold air intake, with an unplugged MAF sensor.

Sidenote, as a condition of the transaction the seller required me to take these wheels that were sitting in the back seat of the car:

In May 2016, I took delivery of my Focus ST. Both the Fiesta ST and Focus ST come with a free day of driving school at Utah Motorsport Campus (formerly Miller Motorsports Park) in Tooele, Utah. Since my day at driving school (doing sick skids and hot laps), I’ve wanted to run autocross and rallycross around Detroit. The only problem is that my ST is a brand new car, and I don’t want to race it; it gets enough abuse as a daily driver. Clearly the solution here is to buy the cheapest running car I can find that is manual and rear-wheel drive, right?

Yes. At least it was for me.

The rest of August and September 2016 were spent scouring craigslist for suitable autocross beaters.My only requirements were; the car must cost less than $1500, and be in good enough condition to get to my garage under its own power. One friend at the lunch table recommended a Porsche 944, my supervisor pushed the Toyota MR2, others suggested the tried and true Miata or come American muscle in the form of older Camaros and Mustangs. True masochists tried convincing me to get a Mazda RX-7 that had clearly lived a hard life as a drift missile.

In reality, no Miata in my price range hadn’t been heavily modified and thrashed within an inch of its life on track. Living near Detroit, older Mustangs and Camaros were (and will be forever) plentiful and any replacement parts would be dirt cheap, but most had V6 engines and they struck me as an unimaginative solution to my racecar woes. I found a Subaru Impreza 2.5RS sedan that was supposedly in good enough condition, but when I went to check it out, I found the bottom of the engine dripping in oil, and the owner couldn’t tell me if the head gaskets had been changed already. Since 90’s 2.5 liter Subaru engines were notorious for blowing head gaskets, I passed since I likely wouldn’t be able to do that repair in my garage.

The next car I found that piqued my interest was a 1986 Toyota Supra, listed for $1100. Listed problems included a cracked windshield, one stuck popup headlight, and a leaky fuel tank, but it would allegedly still run and drive. I contacted the seller to see if it was still available since the listing was over a week old. Almost immediately I get a response that yes, it is still up for sale. I try and arrange to meet up so I can inspect the car in-person and… nothing. I tried calling, texting, and emailing, but I never heard back from the owner. I know they didn’t keel over because the listing continued to be updated, and the price dropped to $800. I’m still sad that I couldn’t buy that Supra.

Eventually I found a ‘94 Mercury Cougar, which seemed perfect because it was listed as manual, RWD, had a V8, and would run and drive, all for $900. I called the owner, and left a message asking to verify that it indeed had a manual transmission and a V8. The owner texted me back the next day saying that Massachusetts (I kept my old cell phone number when I moved) seemed too far away for me to be a legitimate, interested buyer, and that he didn’t want to sell me the car. I assured him that while I do have a Massachusetts phone number, I actually live two towns over from him. Luckily he believed me, and we arranged for me to come look at the car.

When I got to his house, I didn’t see the Cougar outside. I thought it might be in the garage or something until the man answers his door, opens his garage, and leads me through it to his fenced-in backyard. There lay the Coug’. Upon closer inspection, the car is actually an automatic not a manual. Additionally, the car is filthy and there doesn’t appear to be a gate in the fence to facilitate driving the car. I asked the owner about the last time the car had driven. Three months ago, but he assured me that it would start right up with a fresh battery. Ok… The fact that he welded in some extra steel to the front passenger shock tower wasn’t a good indicator of the condition of the rest of the underbody, either. With that, I declined to buy the car, thanked him for his time, and left.