A comedy of errors has worked in my favor

"Flynorcal: pilot, offshore sailor, car racer and panty thief" (flynorcal)
02/25/2018 at 21:06 • Filed to: None

This should be a source of alarm right?

It certainly caught my attention. However, I am pretty sure I’ve worked out what’s going on and why I’m not going to worry too much over it and I’m certainly not going to fix my thermostat. No way, no how.

That picture was taken this morning after my second track session. The first was cut very short — three hard laps and then we all got black flagged and went back to the hot pits to wait to go back out as a spec Miata lost an entire wheel, tire, rotors, calipers and all, and was sitting in a likely impact zone. I’d have just kept on driving myself, but the Miata driver felt the need to spin into the dirt. Some people just can’t handle change I guess.

While sitting there idling in the hot pit my CEL came on and I noticed that the gauge looked even a shade worse than the photo. I went back to the paddock fearing I was puking oil on the track or blew a gasket or who knows what.

Got back, checked the oil, and it was a little low. But you know how dipsticks are sometimes hard to read especially with hot, thin oil but since I ran back five sessions and did a couple dyno pulls the day before I’d walk to the pro shop and get a quart and let the engine cool and a fresh ($20!) quart and a cool engine and my pressure was fine again.

Next session I watched the gauges and all was perfect across the board. Went to the paddock and left the car running at idle to see how it would react and took the above photo.

When I bought the car I noticed the thermostat must have been stuck open as the engine and it’s oil never gets warm enough but it’s a track car so why fix a thing you really don’t care about. It’ll be plenty hot, no need to regulate it. I think this has masked how worn the bearings are in the car by keeping the oil from getting very thin. So there’s always oil pressure. There’s also oil pressure when I’m driving even when it’s hot and thin.

I’ve never driven the car hard and then stopped and sat at an idle before. I now know that it’ll read super low so hey maybe don’t do that.

I think the reason this old engine has lasted as well as it has for as long as it has (130k miles) being abused and neglected is partly due to the neglect.

Had someone bothered to fix that thermostat the engine would run roughly at the same temps as it does on the track (take another look at the photo) this thing would have been running with that low oil pressure every day. This car would have been in the boneyard long ago.

So a big shout out which of long list of previous owners who let the thermostat fail and to all the subsequent owners who never realized or cared that the gauges never pointed where they should. I think it’s what’s kept the car alive.

DISCUSSION (10)

Flynorcal: pilot, offshore sailor, car racer and panty thief > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/25/2018 at 21:49

By the way all the above is what I’ve reasoned out but I could certainly be wrong so if you’ve got a better idea please share. There’s always people way better informed than I so any input is appreciated.

TheRealBicycleBuck > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/25/2018 at 22:24

A common “fix” for the 3.0 Ranger/Mazda is installing a lower-temp thermostat to fight knocking. It never overheats, but it burns more fuel. I wish it had a real oil gauge. The gauge functions more like an idiot light - there’s either pressure or there’s not.

crowmolly > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/25/2018 at 22:32

1.) Could be a non-stock thermostat. LT1s are reverse flow cooling and people have been known to do janky shit because they don’t know how to work on/modify it.

2.) Low oil pressure when hot is kind of an LT1 “thing”. It will kick the light on at ~6psi or lower.

Flynorcal: pilot, offshore sailor, car racer and panty thief > TheRealBicycleBuck
02/25/2018 at 22:34

Perhaps there’s a slim chance someone truly mechanically gifted swapped out the OEM part with a lower temp one when they noticed the bearing starting to go via the dropping oil pressure. That’s some next level ingenuity if so but when mechanics seem the same problem enough times...

Flynorcal: pilot, offshore sailor, car racer and panty thief > crowmolly
02/25/2018 at 22:49

#1 sounds pretty likely as this car is a frankenstein. #2 I didn’t know but it’s not going to get any hotter than ~20 miles flat out as hard as I could push it.

This would mean I’m not only looking at something of a non problem but also a known issue. Maybe the bearings aren’t so bad after all (I hope) as the dyno pull from yesterday indicated a powerplant that’s in more than decent shape.

Thanks for responding. I very much appreciate it.

AdverseMartyr > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/25/2018 at 23:20

The fact that your gauges descend to show an increase hurts my brain. I don’t think I could ever stop panicking over the temp. gauges.

Flynorcal: pilot, offshore sailor, car racer and panty thief > AdverseMartyr
02/25/2018 at 23:24

Out of context, yeah, wow. I totally see your point. In the car on the other side of the little digital speedo is a big RPM gauge so everything swings in a big arc from left to right, so it’s okay when you’re there. I totally see how you’re seeing it though and yes that would be horrible. Up should never mean down and vice versa.

Schaef_Camaero Z/28 > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/26/2018 at 10:05

I’m with crowmolly on this one. ~18-20 psi is pretty good for hot idle in my opinion. Not saying my 205k LT1 is in the best health, but it runs good, doesn’t make any odd noises and at hot idle will get under 10 psi (according to the factory gauge).

Flynorcal: pilot, offshore sailor, car racer and panty thief > Schaef_Camaero Z/28
02/26/2018 at 13:13

Thank you both. As this car doesn’t see any real use other than racing I’m bumping the oil up to 20w50 which should handle the heat a little better without robbing me of many horses. Gonna make that change today and do a little spirited back road driving and see how it handles the change.

atfsgeoff > Flynorcal: pilot, offshore sailor, car racer and panty thief
02/27/2018 at 02:05

Nearly 20psi of oil pressure at idle? Pfft, you’re fine.

Call us when it gets below 5.