T28 Turbo coolant line leak causing overboost/boost leak?? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

claine650 · 03-21-2015, 02:17 PM

S14 sr20det developed coolant leak due to cracked hard line from engine block to turbo.
Started as slowly dripping, hardly loosing much coolant, over the course of a month as it got worse I noticed my boost gauge started reading higher than before the leak started. As of last week the car started boosting to a max of 10-11 psi steady, every pull. car felt like an animal compared to before the leak lol. But as well as the higher boost came so did heavy coolant loss. Today, I pulled off the banjo to the block and wiggled the line and it just came right out, broken off on turbo side. So I got a bolt and washer plugging the block for now and another plug on the water neck to run without coolant for the next week or two til I get my braided lines. First drive after blocking off coolant to the turbo, boost now is maxed out at 5-7 (I think) which is good hopefully since that's around stock.

My big questing to this experience so far is, how does the coolant hard line from the BLOCK to TURBO correspond with a possible boost leak, or cause the car to over boost?

Thanks in advance for any insight or insult.

claine650 · 03-21-2015, 05:08 PM

Well idk now, might have to retract thinking these things were correlated. Went for another drive a little bit ago and I'm still creeping just up around 10 psi, just not loosing coolant anymore. Might have small boost leak somewhere else I still haven't found or just aging wastegate actuator? Not sure..

03-21-2015, 02:17 PM	#1
claine650 Leaky Injector Join Date: Jul 2014 Posts: 96 Trader Rating: (1) Feedback Score: 1 reviews	T28 Turbo coolant line leak causing overboost/boost leak?? S14 sr20det developed coolant leak due to cracked hard line from engine block to turbo. Started as slowly dripping, hardly loosing much coolant, over the course of a month as it got worse I noticed my boost gauge started reading higher than before the leak started. As of last week the car started boosting to a max of 10-11 psi steady, every pull. car felt like an animal compared to before the leak lol. But as well as the higher boost came so did heavy coolant loss. Today, I pulled off the banjo to the block and wiggled the line and it just came right out, broken off on turbo side. So I got a bolt and washer plugging the block for now and another plug on the water neck to run without coolant for the next week or two til I get my braided lines. First drive after blocking off coolant to the turbo, boost now is maxed out at 5-7 (I think) which is good hopefully since that's around stock. My big questing to this experience so far is, how does the coolant hard line from the BLOCK to TURBO correspond with a possible boost leak, or cause the car to over boost? Thanks in advance for any insight or insult.

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03-21-2015, 05:08 PM	#2
claine650 Leaky Injector Join Date: Jul 2014 Posts: 96 Trader Rating: (1) Feedback Score: 1 reviews	Well idk now, might have to retract thinking these things were correlated. Went for another drive a little bit ago and I'm still creeping just up around 10 psi, just not loosing coolant anymore. Might have small boost leak somewhere else I still haven't found or just aging wastegate actuator? Not sure..