I am trying to replace Crankshaft Position Sensor just below on 1998 Hyandai Accent. Tight fit from above. About impossible coming from underneath. However, I cannot determine due to the angle, as to just what type of bolt or screw head that the single bolt is. It looks as if it might be a Phillips. Perhaps a #4, as I do not have a bit that size. I have tried Phillips #3 & #2. But at times, it looks as if it might be a Square (due to the angle), so I have tried up to Square size #3. I have tried Hex & Torx, but to no avail. Also I have tried two security bits that look similar to a Phillips, but they do not grab or sit tight in the slot either.

Has anybody come across this & know exactly what type of slot this is? I have even tried to get visegrips on the outside, but have not accomplished that feat quite yet.

 

Usually, the bolt is taken out using a 10 mm socket
But am not sure about the 1998 Accent.

 

It is at an angle to where it distorts your view from up top. Impossible to tell from below. It looked to be a round head, not the flatter type of a pan head, but I forget what the round style is called that has the thickness of a hex head bolt.

I tried a 10mm as the first thing just in case (the camshaft position sensor uses a 10mm head up above), but it just went around it easily. So much for wishful thinking. So I looked, tried this, looked again. It is just the right angle to where you cannot get a good view on a telescoping mirror.

It looks like it has at least two slots (due to the angle), one going to PS of car, and the other facing below the emngine, which would signify a "+" and chances of being a Phillips slot. But looking at it, it also appears to be a square slot, which could be an internal square head or it could still be a large Phillips slot.

I tried these:
Phillips #2 & #3 bits
small hex bits (up to where they would not fit into the slot)
Torx bits
2 sizes of Security bits (which appear to look close to a Phillips)
Square Heads #1,2,3

I have a Phillips #4 but it is a rather large Irwin screwdriver from the 1970s.

I swung by Lowes late last night (not enough time to get by them and an auto parts store. And I figured I would have a better chance at getting replacement metric bolts/screws & the square head bits at Lowes, so I chose that route.

I got a B&D set which looks like it might have a larger square head bit & I count the 4 different sizes as 4, so I am hoping it has a #4. But I turned up empty on Phillips #4 bits (or even saw a screwdriver, I guess because they are rare, but I have used my Irwin over the years).

About to go attempt it once again in the next hour.

 

Good luck

 

OK, finally done. It seems the screw/bolt head was probably a Phillips #3WO (that is a Phillips #3 Wallowed Out, if you know what I mean. That is nowhere to be putting a #3 Phillips, in such a tight spot & and at a tilt that projects right into the end of another sensor.

I finally pulled the air duct up off from above the radiator. And finally also pulled the driver side electric fan. I grabbed some Phillips #4 bits from town Saturday afternoon, and tried them Sunday, only to find a #4 was too big. Next step was to try & grab a vise grip on the round head. To no avail, as I started shaving the head here & there. Next step was to try & chisel a slit across for a large slot screwdriver bit. That did not work, including a big old PowerCraft screwdriver (from Montgomery Ward back in the 70s). It was short enough to fit in the tight area, but still would not grab. Next on the list was cross chisel to see if I could recreate a Phillips slot. Definitely did not work.

So two other possibilities remained. I could whittle off the head, pull the sensor. Stuff a rag in that hole. Drill out the remainder of the screw & use a tap to clean the threads. Or I could drill a hole in the center & try to use a stud extractor. However, I had a bad experience in 1981 or 1982 when I broke off a Tungsten tap. My cosin (a machinist) came out to survey the damage. He said the only thing that would drill Tungsten was a diamond tip drill bit. I did not have any, so he shared an alternative option, plus how not to let it ever happen again. And it hasn't. But I do cringe when I have to use an extractor or tap.

I decided I had been wanting a close quarters drill. And I tried a regular cordless drill, but not enough room to get in there. Harbor Freight had theirs on sale for $30, plus i could use a coupon & bring it down to $24 plus tax. So I went by after work today, only to find they were out of the corded. And also out of their cordless version too. The truck had just come in & none were on it. And the guy in the back said they may not get any the next week. Bummer!

I swung by the Wal-Mart on that end of the B-CS metroplex here. I found the right angle head by Black & Decker for under $15. I just had to get some drill bits that have the 1/4" hex shank, as that was what kind it requires. Standard drill bits would not work. Broke two bits drilling. Tried one extractor (by B&D), but did not feel comfortable, so I used a spiral flute type for the second try. I tool it nice & easy. Plus I used a wide jaw small adjustable wrench. As I went down on it, the screw head (what was left of it) started turning. However, as I used the extractor, I could tell I had drilled at angle. I am amazed the extractor did not break off. I got the old screw/bolt out. I started to replace it with one with a Phillips #3. But then I decided, No Way! I had gotten an assortment of metric bolts at Lowes for this. I used one with a 10mm hex head.

So the CKP sensor is now in, as well as a new CMP sensor as well. I will put the car back together Tuesday evening, then report on the other thread if I finally got it going. If not, then update as to what all has been done so far.

 

Thanks for the update.
Wow, what a battle with that screw
Smart thing was to use a bolt to replace the screw
Hopefully it won't rust so badly that it won't come out
Phillips and slotted screw heads weren't really made for the kinda of torque that is normally applied to these fasteners

Wishing you good luck and hopes it starts and runs well.
Fingers crossed

 

Hmm, it changed. I had written almost a sentence, then it changed screens on me. OK, sorry so late in response. Got Accent running just before Noon Saturday (Aug. 12th). I kept putting it off every evening due to the heat (Fri & Sat we were under Heat Advisory). A "Brief" is on the other thread. And details have been started, but not finished yet. I will try to get that done in the next few nights. Hopefully it will assist others due to the oddities that occurred.