About a year ago I bought a 97 sc300 with a gte swap, what I was told was a turbonetics t66 (later found out it was just a 66mm turbonetics) and an auto transmission, The swap looked clean and the car drove quite well short of the 115mph limiter and the occasional boost cut when I wasn't watching my foot.
It was running on stock ecu, but my wideband read all the correct numbers at all the right places so I wasn't too worried about it. I wanted to get more out of the car so I bought Map ECU 3 (because I was cheap at the time) I had installed it and started tuning it, but for daily driving I would disconnect it and continue on stock tune.
Right at about that time my wideband readings started going crazy. Anytime I was in boost it would immediately go lean compared to the typical 11.2 I was seeing at WOT a few weeks before. I started to troubleshoot it and found all sorts of things wrong with it, fuel filter was in bad shape (gas running through it looked like coffee with creamer) so I replaced that, replaced my O2 (although I don't really know why) I ran a compression test which came out fairly inconclusive and finally decided to take it to a local shop and have them diagnose my problem, He sent me an email with compression and leakdown test results that looked something like this: Comp test; Cyl 1: 200#. Cyl 2: 200#. Cyl 3: 185#. Cyl 4: 195#. Cyl 5: 200#. Cyl 6: 150#.
Leakdown test; Cyl 1: 11%. Cyl 2: 13%. Cyl 3: 60%. Cyl 4: 15%. Cyl 5: 8%. Cyl 6: 55%. At first I was told it was bottom end damage, but then upon further investigation I was told that it was a headgasket due to bubbling in the coolant reservoir during the leakdown test. When I bought the car I was told that the swapped engine had 35k miles on it. I didn't really believe this but I bought the car anyways.
I decided to pull the head off and replace the gasket and see if that did anything. Basically I pulled the cams out and found a large amount of scoring on a bearing on the intake cam. S**T!!! This car is turning out to be more trouble than it's worth! But it's a labor of love (and hate) I guess. The head is currently being rebuilt with 1mm oversized valves and getting a port and polish.
I will let you know that this is my first turbo car and I am not the most experienced with diagnosing anything. I guess the moral of the long winded intro is next time I am just gonna do the swap myself, during the tear down I have found a lot of port quality work from the previous owner, but with the help of my brother; Pyro15d, I am determined to rebuild this thing the right way.
I will also add that so far I am unsure of whether I am actually going to do a full rebuild or just clean everything up and reinstall it in a more organized and less rushed manner than before.
It was running on stock ecu, but my wideband read all the correct numbers at all the right places so I wasn't too worried about it. I wanted to get more out of the car so I bought Map ECU 3 (because I was cheap at the time) I had installed it and started tuning it, but for daily driving I would disconnect it and continue on stock tune.
Right at about that time my wideband readings started going crazy. Anytime I was in boost it would immediately go lean compared to the typical 11.2 I was seeing at WOT a few weeks before. I started to troubleshoot it and found all sorts of things wrong with it, fuel filter was in bad shape (gas running through it looked like coffee with creamer) so I replaced that, replaced my O2 (although I don't really know why) I ran a compression test which came out fairly inconclusive and finally decided to take it to a local shop and have them diagnose my problem, He sent me an email with compression and leakdown test results that looked something like this: Comp test; Cyl 1: 200#. Cyl 2: 200#. Cyl 3: 185#. Cyl 4: 195#. Cyl 5: 200#. Cyl 6: 150#.
Leakdown test; Cyl 1: 11%. Cyl 2: 13%. Cyl 3: 60%. Cyl 4: 15%. Cyl 5: 8%. Cyl 6: 55%. At first I was told it was bottom end damage, but then upon further investigation I was told that it was a headgasket due to bubbling in the coolant reservoir during the leakdown test. When I bought the car I was told that the swapped engine had 35k miles on it. I didn't really believe this but I bought the car anyways.
I decided to pull the head off and replace the gasket and see if that did anything. Basically I pulled the cams out and found a large amount of scoring on a bearing on the intake cam. S**T!!! This car is turning out to be more trouble than it's worth! But it's a labor of love (and hate) I guess. The head is currently being rebuilt with 1mm oversized valves and getting a port and polish.
I will let you know that this is my first turbo car and I am not the most experienced with diagnosing anything. I guess the moral of the long winded intro is next time I am just gonna do the swap myself, during the tear down I have found a lot of port quality work from the previous owner, but with the help of my brother; Pyro15d, I am determined to rebuild this thing the right way.
I will also add that so far I am unsure of whether I am actually going to do a full rebuild or just clean everything up and reinstall it in a more organized and less rushed manner than before.
