Was on a 2mi drive on my m20b25 when I started noticing it was down on power, unresponsive, and the motor sounded strange below 3krpm but it responded normally above 3k. Stopped at a light, and it died on me. Started it again and it ran for about 30 seconds before cutting out again. Pushed it to a safe spot, towed it, and now here I am diagnosing. At first it would crank over, start, and then misfire violently (enough to shake the whole car) then it would crank, start, and die within 5-30 seconds, then it would crank and start but die immediately and now it only cranks but will not turn over (probably just flooded it) Only thing that changed is that it was parked flat when it would start & run, and it's on a decently steep hill now, where it stopped running.
Only previous long term symptoms were a little valve noise, and the throttle would sometimes lag on very cold days before the car warmed up. Otherwise it was a really healthy m20b25. 250k miles and I have all the previous owner's + my own service history. Just switched from Rotella T to Castrol GTX 500mi ago but I doubt that's related.
SHORT TERM, the past two drives before this happened the coolant temp would fluctuate wildly, but it never overheated; the needle just fluctuated between half and 3/4th. I assumed it was a bad SI or cluster since I have other issues with both, but this may be related to my issue since it started right before this.
Plugs were gapped correctly. Tiny bit of oil on one plug, but otherwise no excessive oil/corrosion on them. The plugs have 15k on them and were clearly on the way out but they were by no means bad enough to stop the car from starting.
After checking the plugs the rain started getting crazy so I had to call it a day as far as diagnostics go.
Any ideas what my issue could be, or what I should look at next time I diagnose? Unless I lost the receipts, the coil packs are most likely ancient, so I'm thinking they'll be the first thing to get replaced. Trying to get it running as cheaply as possible, I took the past few weeks off work and the bus isn't an option for my commute (subcontractor) but luckily I have a friend who will loan me whatever I need to get fixed worst case, but I'm not trying to burn a ton of money replacing maybe's if I don't have to.
Thanks in advance for any advice, I'm stressing hard.
Only previous long term symptoms were a little valve noise, and the throttle would sometimes lag on very cold days before the car warmed up. Otherwise it was a really healthy m20b25. 250k miles and I have all the previous owner's + my own service history. Just switched from Rotella T to Castrol GTX 500mi ago but I doubt that's related.
SHORT TERM, the past two drives before this happened the coolant temp would fluctuate wildly, but it never overheated; the needle just fluctuated between half and 3/4th. I assumed it was a bad SI or cluster since I have other issues with both, but this may be related to my issue since it started right before this.
Plugs were gapped correctly. Tiny bit of oil on one plug, but otherwise no excessive oil/corrosion on them. The plugs have 15k on them and were clearly on the way out but they were by no means bad enough to stop the car from starting.
After checking the plugs the rain started getting crazy so I had to call it a day as far as diagnostics go.
Any ideas what my issue could be, or what I should look at next time I diagnose? Unless I lost the receipts, the coil packs are most likely ancient, so I'm thinking they'll be the first thing to get replaced. Trying to get it running as cheaply as possible, I took the past few weeks off work and the bus isn't an option for my commute (subcontractor) but luckily I have a friend who will loan me whatever I need to get fixed worst case, but I'm not trying to burn a ton of money replacing maybe's if I don't have to.
Thanks in advance for any advice, I'm stressing hard.
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