DIY Turbo Discussion greddy on a 1.8? homebrew kit?

MKTurbo Kit - 220 Degree CLT

Thread Tools
 
Search this Thread
 
Old 12-16-2020, 11:45 PM
  #41  
Senior Member
 
technicalninja's Avatar
 
Join Date: Mar 2017
Location: Granbury Texas
Posts: 668
Total Cats: 190
Default

Originally Posted by Godless Commie
I once solved a similar sounding mysterious overheating problem using an unorthodox technique, so just humor me, and give it a shot.

I fully realize providing ideas and diagnostic info for a car without seeing or getting a feeling for it, and by solely generating ideas based on (however detailed they may be) on written forum posts is far from ideal, and I may be inadvertently misled in the process.

With my disclaimer out of the way, let's get to it.

A lot of shops have gas analyzers. I used to have one, and it was an incredibly valuable tool to have.

All you need to do is remove the radiator cap, drain/syphon some of the coolant out (or use a tight fitting funnel on the radiator neck) and get the car good and hot, hold the tip of the gas analyzer probe just inside the rad neck (or the funnel) and brap brap brap the engine as you watch the analyzer screen.
If you have any kind of exhaust gas migration to the coolant, it will definitely be apparent in the form of rising CO and HC values. (Brap braps will force a rich condition, and increase exhaust pressure to exacerbate the problem, if the problem stems form the above mentioned condition)
This test will take however long it takes to get the engine hot. You can also keep checking it as it warms up. Sometimes temperature plays a major role, because certain leaks/cracks/seepages act differently when cold or hot.

Like I said, I used this method as a last resort once, and got results.
You will not lose anything, and even if this test gives you a definite negative result, you will have crossed some of the usual suspects off your list.

(For the record, brap brap means revving and letting go of the throttle repeatedly.)
He's right. I've done exactly this as well when an analyzer was present.
This kit will do pretty much the same thing
Amazon.com: Block Tester BT-700 Combustion Leak Test Kit in Hard Case - Made in USA: Automotive Amazon.com: Block Tester BT-700 Combustion Leak Test Kit in Hard Case - Made in USA: Automotive

You can turn the fluid yellow with your breath and then back to blue by pumping air through it.
It can color change multiple times. I test it before I use it.
It's pretty accurate as well. I believe in my tester.

Last edited by technicalninja; 12-16-2020 at 11:50 PM. Reason: Only the ninja knows...
technicalninja is offline  
Old 12-17-2020, 08:56 AM
  #42  
Retired Mech Design Engr
iTrader: (3)
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,009
Total Cats: 857
Default

Originally Posted by Godless Commie

(For the record, brap brap means revving and letting go of the throttle repeatedly.)
@Godless Commie Good to see you more active on the forum these days.
DNMakinson is offline  
Old 12-17-2020, 09:43 PM
  #43  
Junior Member
 
natewin's Avatar
 
Join Date: Jan 2019
Location: NH
Posts: 146
Total Cats: 23
Default

Check what things are wired to your Sensor Ground wiring. I have a wideband that has a wire labeled as sensor ground. When I hooked that to the car senor ground when the wideband heater cycled, my fans would kick on. I assume this was because of the ground offset from the high current grounding through sensor ground. The coolant gauge seems particularly sensitive because every time the wideband cycled I could watch temps spike with it. This went away when I got the wideband wiring off of sensor ground entirely.

natewin is offline  
Old 12-18-2020, 10:53 AM
  #44  
Newb
Thread Starter
 
DFWMike's Avatar
 
Join Date: Nov 2020
Location: N Dallas
Posts: 15
Total Cats: 0
Default

Originally Posted by shuiend
How did you burp the cooling system? Something is definitely off.

If the car is just sitting and idling do both fans turn on and then when temps drop to the point that they turn off?
Yes, fans kick on at 208 i believe... whatever the default is for MS and it drops temps right back down
DFWMike is offline  
Old 12-18-2020, 10:54 AM
  #45  
Newb
Thread Starter
 
DFWMike's Avatar
 
Join Date: Nov 2020
Location: N Dallas
Posts: 15
Total Cats: 0
Default

Originally Posted by natewin
Check what things are wired to your Sensor Ground wiring. I have a wideband that has a wire labeled as sensor ground. When I hooked that to the car senor ground when the wideband heater cycled, my fans would kick on. I assume this was because of the ground offset from the high current grounding through sensor ground. The coolant gauge seems particularly sensitive because every time the wideband cycled I could watch temps spike with it. This went away when I got the wideband wiring off of sensor ground entirely.
my gauges are wired to the power/ground for the now non-existent stereo
DFWMike is offline  
Old 12-18-2020, 12:06 PM
  #46  
Supporting Vendor
iTrader: (1)
 
turbofan's Avatar
 
Join Date: Sep 2010
Location: Lake Forest, CA
Posts: 7,957
Total Cats: 1,009
Default

Perform a block test using the tool Technicalninja posted.

If you don't want to buy the whole tool, Oreilly will loan them, you just have to buy the fluid (less than $10).

Do that, then report back. It's worth a try, easy to perform.
__________________
Ed@949Racing/Supermiata
www.949racing.com
www.supermiata.com
turbofan is offline  
Old 12-18-2020, 03:24 PM
  #47  
Junior Member
 
natewin's Avatar
 
Join Date: Jan 2019
Location: NH
Posts: 146
Total Cats: 23
Default

Originally Posted by Das
I'm a little envious. My supermiata reroute stays around 160-170 degrees.
​​​​​​​
Mine does the same as this, I keep wondering why.

Last edited by natewin; 12-19-2020 at 08:33 AM.
natewin is offline  
Old 02-21-2021, 12:00 AM
  #48  
Newb
Thread Starter
 
DFWMike's Avatar
 
Join Date: Nov 2020
Location: N Dallas
Posts: 15
Total Cats: 0
Default

Sorry for the delay guys, it's been a little hectic with work, family, and Texas freezing over.

I dropped the car off at MER in Cresson because I was sick of diagnostics. The culprit was a bad ground on the intake manifold (not one i touched and didn't know was there) along with some less than stellar wiring on my part. I wanted to follow up since there's so many posts claiming a problem but with no solution.

According to MER, they cleaned up the wiring connections I had made along with checking all grounds. The grounds were all good except for the harness ground that connects on the underside of the intake manifold towards the rear. It was hard for me to see but apparently there's one back there. I'm going to take the car out and check the tune since there's a decent chance it has some bad input data. I would provide pictures but it's incredibly hard to get a phone back there to capture it.

If you're reading this because you have the same problem: read up on the wiring harness in depth and double check ALL grounds, connections, and plugs. Thanks everyone for the suggestions and help

FWIW: I did a leakdown and compression test before I dropped the car off and both had good results so it wasn't a headgasket, cracked block, or anything else.
DFWMike is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
YankyMate
General Miata Chat
6
07-06-2018 04:08 PM
tyhackman15
General Miata Chat
2
10-11-2017 12:19 PM
LukeH
Engine Performance
36
09-11-2015 10:09 AM
Mech5700
DIY Turbo Discussion
28
12-18-2014 09:55 PM
levnubhin
General Miata Chat
62
02-09-2009 08:48 PM



Quick Reply: MKTurbo Kit - 220 Degree CLT



All times are GMT -4. The time now is 04:04 AM.