I give up! One for the experts..

JohnRardin

JDM 7MGTE
Apr 4, 2006
110
0
16
Radford, VA
My 89' turbo keeps overheating and I've replaced the entire cooling system. The thermostat works, I just installed a fluidyne and a new wate pump and nothing drips. The wierdest part is that my temp guage never went above half way but it definately overheated.

Heres what scares me:

I feel a lack in torque and the turbo boosts way too strong and way too soon. Worst of all it doesn't make anywhere near the power that it should under boost. My boost guage read a stronger vac than I've ever seen which tells me theres no leak (about -550 bar when typically its about 425).

My best guess is that I didn't install the CPS correctly and my timing is off. I've done CPS installations plenty of times and usually if its wrong it just won't run. Once it warmed up (which happened faster than it should), it backfired badly when I let off which is a timing issue but after a minute...it went away and the CEL went off!

I assumed it was just th ECU relearning everything but shortly after I pulled over to see why it was lacking power and it cut itself off. The entire engine steamed like it was way too hot but my guage read normal temp!

Could the wrong timing cause all of this or is there something else? I'm really stumped and I'd greatly appreciate any ideas you guys have. THANKS GUYS!
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The Legend Condominium Cosy Beach
 
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suprarx7nut

YotaMD.com author
Nov 10, 2006
3,811
1
38
Arizona
www.supramania.com
What code did it throw when you had the CEL light on?

You need to check the timing. If you don't have a timing gun, get one.

How on earth do you know it overheated when the temp gauge did not move?
 

adampecush

Regular Supramaniac
May 11, 2006
2,118
3
38
Edmonton
JohnRardin;1321452 said:
Everything but that.. would that affect anything? The heat blew hot so I don't expect that to be an issue

if it is leaking, it will suck in air when the car cools down, possibly giving BHG-like symptoms.

Have you verified your timing with a timing light? If not, do that first before trying anything else. Improper timing can cause a ton of different problems, including many of the ones you mention.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
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Valley of the Sun
1) - Timing can cause higher than normal engine temps. There has been no mention of any timing check with the diagnostic block jumped.

2) - A NAPA block tester will check for exhaust gas in the coolant system, but there has been no mention of coolant coming out of the overflow bottle. A compression test is in order here.

3) - Steam coming off the engine? Has the coolant system been pressure tested? Has the gauge temp sensor been tested per the TSRM to confirm a supposed/perceived error?

Need to confirm a few things 1st before "guessing" at possible causes.
 

JohnRardin

JDM 7MGTE
Apr 4, 2006
110
0
16
Radford, VA
jdub;1321492 said:
1) - Timing can cause higher than normal engine temps. There has been no mention of any timing check with the diagnostic block jumped.

2) - A NAPA block tester will check for exhaust gas in the coolant system, but there has been no mention of coolant coming out of the overflow bottle. A compression test is in order here.

3) - Steam coming off the engine? Has the coolant system been pressure tested? Has the gauge temp sensor been tested per the TSRM to confirm a supposed/perceived error?

Need to confirm a few things 1st before "guessing" at possible causes.

The cooling system holds pressure fine. It never even lost any water when it overheated. I'm starting to fear that its a BHG and timing. I haven't tested the gauge per TSRM but I did install a new thermo housing with working sensors. The gauge moved faster than usual but never went above say %45. BHG?
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Wong Amat Tower Condominium
 
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jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
38
Valley of the Sun
JohnRardin;1322006 said:
The cooling system holds pressure fine. It never even lost any water when it overheated. I'm starting to fear that its a BHG and timing. I haven't tested the gauge per TSRM but I did install a new thermo housing with working sensors. The gauge moved faster than usual but never went above say %45. BHG?

Holding pressure and a pressure test is two different things. A pressure test will tell you if there is a small leak in the system that is allowing air in. Or, is allowing coolant to escape producing the steam you mentioned earlier...it has to be coming from somewhere. Steam just doesn't "appear".

Working sensors is a relative term...any used part is suspect. I does appear your gauge/sensor is working correctly, but there is only one way to eliminate the possibility vs assuming the sensor is good.
Have you pulled the ECU codes yet?

You really, really need to check timing per the TSRM (diagnostic block jumped)...retarded timing will cause high engine temps and cause the car to run like crap. I guess you could pull the head instead and check the HG...seems like a lot of work to avoid a few tests/checks though. Or you can keep guessing without any hard facts too :sarcasm:
 

kotu100

Active Member
Nov 23, 2006
1,899
0
36
Easton, Ma
put the engine to 0 degrees on the crank mark, make sure piston 1 is at tdc, make sure the cam gear marks line up, make sure the dowel pins are in the correct positions, then make sure your cps looks like this.
p1322035_1.jpg



then go get yourself a timing light.
 

JohnRardin

JDM 7MGTE
Apr 4, 2006
110
0
16
Radford, VA
kotu100;1322035 said:
put the engine to 0 degrees on the crank mark, make sure piston 1 is at tdc, make sure the cam gear marks line up, make sure the dowel pins are in the correct positions, then make sure your cps looks like this.
p1323048_1.jpg



then go get yourself a timing light.

I used this pic when I installed it but apparently i was a tooth off. Luckily, my mechanic says it was all timing. I'm really hoping that it's the only problem. In the past when I installed the CPS wrong it wouldn't even start. This time I'm letting my mechanic handle it that way its sure to get done right this time.
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Franky_S live
 
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JohnRardin

JDM 7MGTE
Apr 4, 2006
110
0
16
Radford, VA
jdub;1322022 said:
Holding pressure and a pressure test is two different things. A pressure test will tell you if there is a small leak in the system that is allowing air in. Or, is allowing coolant to escape producing the steam you mentioned earlier...it has to be coming from somewhere. Steam just doesn't "appear".

Working sensors is a relative term...any used part is suspect. I does appear your gauge/sensor is working correctly, but there is only one way to eliminate the possibility vs assuming the sensor is good.
Have you pulled the ECU codes yet?

You really, really need to check timing per the TSRM (diagnostic block jumped)...retarded timing will cause high engine temps and cause the car to run like crap. I guess you could pull the head instead and check the HG...seems like a lot of work to avoid a few tests/checks though. Or you can keep guessing without any hard facts too :sarcasm:

Haha, I appreaciate all the good advice. And you were right about the timing causing all of these problems. I'm sure the cooling system holds pressure because like I said it doesn't drip and it released pressure through the reservoir tank.

Can a faulty temp gauge only show up to normal temp and stop? Usually they're accurate or completely broken....right?

Since my cars at the shop I can't check codes but I don't expect it to be related since it did that before this happened. I'm just relieved to hear its not a BHG. WHEW!!
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INFANT DEPAKOTE
 
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