I think I blew it up

[plastick]

Hey guys! So after 4 years with an S280 on 93 octane and most recently a full XDI fuel system on E50 (making 360whp) I’ve started to notice coolant consumption. I also blew out all 4 injector seals and had to reseal all of them with a GDI tool. That fixed the misfires but I’m now getting random knock at low load (setting off gently from redlights) or even on decel. My car’s suspension is brutal and I have some rattles because of it (going back to stock suspension in the spring) and I’m wondering if maybe a bad exhaust hanger or leaky water pump making noise is causing the knock sensors to go off sometimes? Car pulls hard but this is also the first winter I’ve driven it with the XDI HPFP.

The car consumes about 1 quart of coolant every 6 months now. I’ve since switched back to 93 and I baby it to and from work. I’m assuming I have block deformation or cylinder liner cracks that are causing coolant to get into the cylinders and cause detonation.

My question is this: is anyone running the Mountune MRX short blocks? The new one seems to convert the block to a semi closed deck and eliminates the cooling slits between cylinders. I’m assuming I could safely run 360-380whp on one of these. Who here has taken the plunge?



I love the car and I only owe 5K on it, it’s got 64k miles and no rust so I wanna rebuild the motor. I think a bulletproof short block would be sweet and just wondering if anyone has done it!

I’ve got the cash thanks to a 401k loan. I’m just waiting for my local engine builder to quote me on refinishing the head to mate with the new MRX short block.

Please post your stories about this process if you’re going through something similar!

MRX Shortblock with CSS

 

[Intuit]

 

[plastick]

View attachment 59952

I used this joke at work today and it had amazing results. Thank you

 

[Mega ST]

One quart every 6 months? How many miles is that? Any smoke? Look at you plugs. Do the look contaminated by coolant? I wouldn’t be super alarmed at that rate of consumption. Head could be lifting a little under full boost? Do a pull. Do the hoses feel bloated. After cool down remove the coolant cap and if it sounds like opening a soda then…. Possibly HG.

 

[plastick]

One quart every 6 months? How many miles is that? Any smoke? Look at you plugs. Do the look contaminated by coolant? I wouldn’t be super alarmed at that rate of consumption. Head could be lifting a little under full boost? Do a pull. Do the hoses feel bloated. After cool down remove the coolant cap and if it sounds like opening a soda then…. Possibly HG.

It’s the head gasket. Shop boroscoped it and it’s leaking down the cylinders.

I just ordered a new engine and will be moving my S280, HPFP and big injectors all over to the new motor. I am going to strip the blown motor down to bare block and get it sent out to be CSS’d with OE bore.

Just for you guys here’s info on how long it lasted:

64k on motor, bought it stock with 32k and immediately went S280. Ran 93 for 2.5 years with no problems. Installed HPFP and turned it up, car made 393whp/397wtq on a mustang dyno. It lasted about 6 months at that power level lmao.

I’m just gonna keep this new motor on 93 until I finish my build

 

[dhminer]

It’s the head gasket. Shop boroscoped it and it’s leaking down the cylinders.

I just ordered a new engine and will be moving my S280, HPFP and big injectors all over to the new motor. I am going to strip the blown motor down to bare block and get it sent out to be CSS’d with OE bore.

Just for you guys here’s info on how long it lasted:

64k on motor, bought it stock with 32k and immediately went S280. Ran 93 for 2.5 years with no problems. Installed HPFP and turned it up, car made 393whp/397wtq on a mustang dyno. It lasted about 6 months at that power level lmao.

I’m just gonna keep this new motor on 93 until I finish my build

Close to 400whp on a Mustang dyno, damn! I’d say was inevitable that you got some head lifting there. You going with a new factory engine or something like a mountune or pumaspeed block?

 

[Mega ST]

Amazing it lasted 6 months at that level. Stock head bolts and all. On a Dynojet that would be like 450ish. Ever run at the track or do any dragy runs?

 

[XR650R]

You exceeded what the stock engine can do. Anything over 300 is the limit.

 

[dhminer]

You exceeded what the stock engine can do. Anything over 300 is the limit.

Generally that’s pretty true, but folks like @TyphoonFiST been running 340+ whp for years without issue

 

[XR650R]

Generally that’s pretty true, but folks like @TyphoonFiST been running 340+ whp for years without issue

Maybe 340 is the limit, then?

 

[dhminer]

Maybe 340 is the limit, then?

Lol! I’m going to cap mine around there for a street tune and 300-320 for the track

 

[Intuit]

Just a reminder that regular oil analysis will inform of some of the potential wear/failure points. Each vehicle will experience different points of failure at varying points in time. There are obviously some failure points that oil analysis won't cover.

 

[Mega ST]

Just a reminder that regular oil analysis will inform of some of the potential wear/failure points. Each vehicle will experience different points of failure at varying points in time. There are obviously some failure points that oil analysis won't cover.

If only it could tell you when your cylinders are becoming egg shaped. I did it once when I had a 4G63T fail on me. Oil and coolant never mixed and minimal bearing material for such a high HP engine. Def very useful when road racing.

 

[Raziel510]

I'm X57RS 30psi at 330hp Dynojet also running xdi hpfp and Jag 30% injectors. I opened mine up cause I was overheating and consuming coolant quickly and my catchcan had the milkshake in it. I had just crossed the 100k milestone but had already had the turbo for 25k miles but the fuel mods for about 15k miles. It's a 2019 and I've been the only owner since 21 miles. When I opened it up there was plenty of coolant in cylinder 3. Since it's my daily and my work truck I bought the pumaspeed shims because of a crack in cylinder 3 with evidence of cylinders 1 and 2 starting to crack or about to crack. I installed the shims with the toughest one to install was between cylinders 2 and 3. New gasket, timing belt only(reused the original tensioner), new head bolts, new pulley bolt, and added the barsleak copper seal. First startup was rough but it has been improving with every drive. Now I gotta save up for either a MRX short block and MRX head setup 7.5k compared to almost 10k for MRX long block. Other option is the pumaspeed bluetop 8k for fully assembled long block.

 

[Intuit]

Nice picks. No cracks in the head from trying to compress liquid? I'd imagine much of that coolant spilled out of the head as the fasteners were loosened and it was pulled. I used the flakes with a prior engine; no disassembly. Like yours it would improve with each hot/cold cycle. But I had to stay out of the accelerator so... nothing beyond "nromal" cylinder pressures of extra normal driving.

 

[Raziel510]

The pumaspeed shims help. I'm able to give it the beans but my mind says nope just take it easy. I get to 30 psi but I only do a quick burst of acceleration. Scary to drive it like this but I'm able to drive it. Sucks when all the ricers and cuhhs(Edgars) wanna race. Good thing my car makes a lot of noise so they back off😂

 

[TyphoonFiST]

Maybe 340 is the limit, then?

Literally*

 

[dhminer]

Literally*

lol I jinxed you

 

[waverider57]

I used this joke at work today and it had amazing results. Thank you

I wouldn't have...
😣