Huge vacuum loss (no brakes) after head install, wrong camshafts?

[Spoolin4Ever]

I bought a "rebuilt head" off &C Enterprises on ebay, some people have had good results so I gave them a shot.

I noticed the camshafts had different letters than my head, but after some research it seems there are all kinds of markings on them, so I figured it must be normal.

Besides that the head looked pretty good; the exhaust valves all said 6t on them, so I took that as a good sign.

I get the head on and start it, and it runs like crap. Practically zero vacuum even on decel and idle (actually it won't really idle). It can only boost up to 3 lbs.

There is a lot of noise like air hissing sounds like it's coming from the exhaust manifold area, but the nuts on there are all tight.

The power brakes don't work. The brake booster hose is connected to the intake, but it is really hard to press the brake pedal. Also, there is a long pause from when you press the gas for it to accelerate, and also when you let off the gas, a longer than normal time for it to stop accelerating.

I have not set the CAS yet, but it doesn't even run well enough to bother getting a timing light yet.

One other thing I noticed; when I was turning it over by hand, much easier to turn over than my head I had before. Like you know when you do your timing? there is that part where it resists quite a bit? This head is much easier to turn by hand for some reason. Is that cam related or more springs?

Based on there being so little/no vacuum, and can only boost to 3 lbs, could this be simply the wrong cams?

Here is my original post about the head and cams, I posted in the wrong forum a while back, it has pics of the cams:
http://www.dsmtuners.com/forums/tun...27597-stock-camshaft-markings-turbo-head.html

and I'm gonna call them tomorrow.

 

[talontd92tsi]

This sounds like a massive boost/vacuum leak. Perhaps you forgot to put the intake manifold gasket on or it got pinched during installation? The vacuum line that operates the brake booster goes straight to the intake manifold so that's where I would focus my search.

I would personally do a boost leak test and listen for leaks in that area. If you are only able to produce 3psi of boost I can almost guarantee that it will make itself known pretty quickly. On another note, it would be wise to not try to boost the engine with this happening, as you could over spin the turbo and damage it due to this leak. Does your boost gauge show vacuum? If so how many inches are you pulling?

EDIT: It is possible that you didn't get the timing belt properly aligned and this could cause a lot of damage to that nice clean head you just installed. Might want to check that too.

 

[Lou98GSX]

did you line up all the timing marks before removing head that way when you put the new head on all you have to do is make sure both dowel pins on cams are facing up so you don't hit any valves when tightening down head . don't know if you have balance shafts those will have to be timed to.if you did that right double check your timing belt see if all the marks line up properly .

 

[Aproductions]

Like these guys have said. I would check or better yet redo the timing completely. But I would first do a boost leak test because obviously the brake booster runs on vacuum.

Oh and check the brake booster hose to make sure the check valve is working 100%.

Post back with results and keep us updated.

 

[BogusSVO]

Even if you had NT cams, the car would run and idle smooth

a few degrees on that cam or a few thousands lift on this cam would not cause what you are discribing...

 

[XiKeiyaZI]

There is a check valve in your Brake Booster line. If it is not working then you will experience the symptoms that you have. You will also blow your brake booster if you continue driving it, and trust me - replacing a brake booster is a pain in the ass. Take off the hose and blow into both sides. Air should only be able to pass through it one direction.

Aproductions is on the right track here.

 

[Spoolin4Ever]

This sounds like a massive boost/vacuum leak. Perhaps you forgot to put the intake manifold gasket on or it got pinched during installation? The vacuum line that operates the brake booster goes straight to the intake manifold so that's where I would focus my search.

I would personally do a boost leak test and listen for leaks in that area. If you are only able to produce 3psi of boost I can almost guarantee that it will make itself known pretty quickly. On another note, it would be wise to not try to boost the engine with this happening, as you could over spin the turbo and damage it due to this leak. Does your boost gauge show vacuum? If so how many inches are you pulling?

EDIT: It is possible that you didn't get the timing belt properly aligned and this could cause a lot of damage to that nice clean head you just installed. Might want to check that too.

Well I put the intake on the head out of the car, and I know the gasket is on there, probably didn't get pinched since I did it off the car...never know though.

The brakes worked fine before the head swap, I will try blowing on both sides of the booster hose just in case.

My boost gauge shows vacuum and it's at zero most of the time, like on even on decel and it won't idle so I can't say about the vacuum at idle.

did you line up all the timing marks before removing head that way when you put the new head on all you have to do is make sure both dowel pins on cams are facing up so you don't hit any valves when tightening down head . don't know if you have balance shafts those will have to be timed to.if you did that right double check your timing belt see if all the marks line up properly .

Yeah I thought the timing we fine, I lined it all up (this is my 3rd time yanking this head, so I have some timing belt practice). I don't have BS belts, removed long time ago (properly).

Like these guys have said. I would check or better yet redo the timing completely. But I would first do a boost leak test because obviously the brake booster runs on vacuum.

Oh and check the brake booster hose to make sure the check valve is working 100%.

Post back with results and keep us updated.

Yeah I will check for boost leaks and check the timing belt setup.

Even if you had NT cams, the car would run and idle smooth

a few degrees on that cam or a few thousands lift on this cam would not cause what you are discribing...

Ok thanks for helping me at least get that doubt out of my head. But what if they were cams from a completely different vehicle? It's hard to say isn't it or am I wrong?

There is a check valve in your Brake Booster line. If it is not working then you will experience the symptoms that you have. You will also blow your brake booster if you continue driving it, and trust me - replacing a brake booster is a pain in the ass. Take off the hose and blow into both sides. Air should only be able to pass through it one direction.

Aproductions is on the right track here.

I'll check it out....

 

[crimsondragon]

Have you checked the head over before the install? Do a compression check.

 

[Spoolin4Ever]

What if the head gasket didn't quite seal right could that do it?

 

[Lofty]

Do a compression test. Im willing to bet money it's not the head at fault here but ive been wrong before. Have you pressurized your intake system yet? If no, then why are you still asking questions

 

[Spoolin4Ever]

Do a compression test. Im willing to bet money it's not the head at fault here but ive been wrong before. Have you pressurized your intake system yet? If no, then why are you still asking questions

Cause it's 2Am cold and windy.

Hey if I didn't put the exhaust manifold studs in the head tight enough could that do it?

 

[BogusSVO]

Well even if the cams were from the Hyundai version of the 4g63, it would still run, but if you mean cams from a 420A got put in.. well they just would not fit in the head casting.

 

[Spoolin4Ever]

Well even if the cams were from the Hyundai version of the 4g63, it would still run, but if you mean cams from a 420A got put in.. well they just would not fit in the head casting.

So I don't have to worry about the possibility of them just tossing some random cam from just any old car because it will only accept cams that would allow it to run basically?

I'm wondering if my head gasket is not on right or something. I mean I'll double check the timing and for boost leaks but I thought the hissing was coming from the exhaust side of the engine.

I will be checking it out later today.

 

[Aproductions]

Do a compression test and a BLT already! haha

 

[Spoolin4Ever]

Do a compression test and a BLT already! haha

I'm actually kind of hungry and I think a BLT sounds really good!

Cars on the other side a town....gotta work up my motivation

 

[Spoolin4Ever]

Well I get the Newbie Award! Friggin forgot the injector seals in the old head! That's what was causing the huge leak. Yeah I know, how stupid, right!

Then I used the home depot seals and for some reason those were crap. One tore, one had fallen out (didn't know it though when installing them) and one just plain wouldn't seal. Found some old hard ones and got lucky, they worked. Of course that was after I broke one fuel rail bolt trying to get the other ones to seal, and broke the wires off of an injector clip

From now on every Vfaq for doing a head should remind you to pull the half moon seal and injector seals on a head swap! it's always something.

RESOLVED..