Tim Baker

True. Maybe the control valves are bad or perhaps it is just clogged. I just remember when I was fixing the interior and mmi the vents had this residue on them that reminded me of oil. But the coolant in these cars has a lubricant and anticorrosive agent in it and it may have been evaporated antifreeze. I just wish I'd have noticed it when I had the dash out. I will surely pressure test It tonight and find out. According to odis there is two heatercore a passenger and a driver but neither it nor bently have very great directions for removal. I know it is simpler to remove on this than the c5 but I'm not sure by much.

anyways its second to fixing the engine oil leaks and issues. as far as the intake cleaning I've been making slow but arduous process. You can see in the pictures below the results so far.

one other question in order to remove the oil separator cover or block ventilation cover I need to remove the solid coolant pipe which runs to the heatercore. I removed the bolts but it is firmly stuck. What is the secret to removing it. The pipe is in the first picture.

Solid pipe running from under thermostat to heatercore. I cant get it out.


Lower intake manifold passenger side

Bottom of lower manifold

Tim Baker

so i started cleaning the intake valves today. i got most the carbon off the first one i started and sprayed some cleaner in it to get it the rest of the way clean. i noticed the cleaner seemed to leak. i quickly sucked it all out and now if i look in the cylinder it looks like there is a bunch of oily liquid in there. my guess is even though the valve looked closed, it isn't. i'm in over my head on this one now and the only solution i can think of is removing the head. does anyone have some advice please?

jonzie77

If I were doing this job on my car I probably wouldn't sweat the leakage since the valve was probably close enough to fully closed that you didn't get any carbon into the cylinder. Also, it sounds like you reacted quickly enough that the amount into the cylinder was minimal. What were you using as a solvent? I would turn over the engine a little by hand just to be sure the valves in question are closed and try a "leak test" again. Did you do a compression check before taking it apart? You could possibly do one at this point assuming you take the fuses out of the two fuel pump locations. I do not know if the car will allow you to spin the starter at this point but it is not too involved to try. You could probably put voltage directly to the starter but it would be a good idea to disconnect any wiring to the car first. Although you can possibly do this job and only have to turn the engine once but I would feel more secure turning it six times so as to be more sure the valves are closed which is close to 1.5 turns of security.

Tim Baker

I did do a compression check prior to this, all 3 cylinders on this side were low compression around 120 psi while the passenger side is 150.
I am using CRC gdi valve and intake cleaner. It dissolves the carbon like nothing. I did start to crank the engine a bit when it happened but havent worked on it much more. I was afraid to spray anything else in the valves. And when I scoped the cylinder it looked like there was actually some oily carbon in it.
A couple notes
I tried blowing air into it to get it out and some came out the fuel injector hole and it was a black sludge like substance but not very much at all.
to do a leak down test now would be difficult because I've removed the injectors to rebuild them. It appeared all the injector seals were bad. In fact some of the metal things that go around the injector were stuck in the engine due to hardened gunk. It reminded me of what happens when someone pours stop leak in an engine but mind you that was in the injector tubes. I'll try to get a pic of it.
The leakdown test I did previously revealed little no air coming from dipstick and no air going into neighboring cylinders... the cylinders all held compression well.
I could complete the injectors and reinstall them but I'm sort of leaning towards taking at least the driverside head off, but of course dont want to.
sort of at a standstill while I try to figure it out.
another thing to mention is that what started this whole job is that my cam girdle seals around the spark plug were leaking oil into the tubes and the pcv was sucking oil out of the crank into the intake so the black sludge in the cylinder very well could have been from that.
like i said in the title i honestly dont know how this engine ran let alone put out the kind of power it was. I literally drove the car up til the day I parked it in the garage and decided to do this work so I never imagined running into all these issues. I considered a few options one being to fix the injectors then reinstall them then apply compressed air to each cylinder as I clean the intake valves to force them shut. But it really seems like a stop gap. I cant imagine the rings are in good condition being as it seems to need a valve job :/ but according to the leakdown they're okay.
Anyways I appreciate the replies.
if I get ambitious tonight or tomorrow I'm going to take the valve covers off so I can double check which are closed and which are open. When I first started it appeared cylinder 2 and 6 were open and the rest closed (assuming the cylinder order looks like

3 6
2 5
1 4

anyways here's a couple more pics of this job.


An example of the gunk in the injector holes

This is the cleaner i tried. Its mesnt to be ran through the intake while the car is running but i said f it and tried it. Works better than anything i ever tried. Sadly costs between 10 and 20 dollars per can.

Intake valves i cleaned that seemed to not seal.

An example of how disgusting the injectors were.

Tim Baker

I cranked the engine around and took a picture of the inside of that valve with it open it seems like it doesnt have a smooth edge to seal to the head completely however maybe It didnt leak much fluid at all because i sprayed some of the fluid in a cup and it bubbled and evaporates really quick leaving just about half the fluid I sprayed within 5 minutes. The sludge that was in the injector hole might have just been that some of the fluid went down that hole and mixed with oil from the cylinder since there was some oil in there. I'm not sure. But I am going to continue this job for now I'm not sure why it originally looked like 2 cylinders had open valves also because when I manually crank it seems like there is never more than 1 open at a time except for a very brief moment. I guess I must have shut the engine off at just that point.
also I hear the tensioner clicking each revolution. I have read it does this when it has no oil pressure. Anyways I'm glad I decided to clean the carbon before doing the timing and cam girdle seals because otherwise I wouldn't have been able to crank it

Tim Baker

So... I have a sand blaster. I am done trying to do this cleaning with a pick and brushes, i spent 12 hours today on 2 cylinders and neither are close to done. I need to know what the recommendations are for where to get the walnut shell media for abrasive blasting.

jonzie77

That is the same solvent I used to reduce the carbon in my engine. I took pictures before the treatment but not after because I'd rather be driving it The fact that you declared your injector seals bad should actually be good news I would think since that could explain some of your compression losses. I think you're on the right track and like you, I would exhaust all such possibilities before I remove a head not that it scares me either. The walnut shell media is a great idea especially if you let some of that solvent loosen it up for a while and as far as where to get the media it turns out that Harbor Freight has no less than two different grades and with any luck you have one not too far away. I don't want to drag on to much here but I think we are in a similar frame of mind which is to have the greatest effect with the least amount of work/money. As an example, as mentioned above, I took off my upper intake manifold to get an idea as to how much carbon I had going on, looked a lot like your pictures actually, anyway most people would insist on replacing the seals but I found mine to be supple enough so I just re-used them even though they were 170.00 miles old. I realize they are not that expensive but if they ain't broke .... So no sign of any problems from that decision and when I go back in to clean the carbon I will replace the seals at that time. Please keep up the excellent documentation I look forward to you getting this right for a reasonable investment.

Tim Baker

thanks for the replies jonnie
I am getting ready to go over to harbor freight I found it on their website shortly after posting this last night. Not sure why I didn't think of this as an option earlier lol. Anyways they list medium and fine grain 25 pound bags. And the more I thought about it, I was happy that my injectors were filthy and had bad seals because exactly like you said that might be some of my compression losses, between that and the bad cam girdle seals and corroaded sealant on the driver side maybe it will increase my compression. Monday I will have OEM spark plugs along with a few other parts. I read somewhere to check the resistance on my spark plugs and that OEM are rated at 1k ohms... mine tested at about 4k average. All of these issues were likely contributing to the misfires. So anyways this weekend I plan to fix the head cover gaskets, walnut blast my intake and check out my timing tensioners. I'll keep posting the pictures. Thanks for the reply and encouragement
here's a picture of my injectors cleaned up as a before and after. I havent Installed the rebuild kits yet but I expect it will help alot.


After cleaning

Befote cleaning

Tim Baker

So today I got the walnut shell blasting supplies. Boy is it messy. By the time I built a sufficient blast gun (out of some brake line) it was dark and I couldn't continue. I did however get one port on the lower manifold done while trying it out... alot easier than brushes damn 30 seconds of blasting had it like new. Tomorrow I'll get the valves done. I got to tape off the engine and surrounding area first.

After 30 seconds of walnut shells at 90 psi... much better than doing it by hand... unbelievably so.

My blast gun vacuum combo to sit over the top. Used a radiator hose and a brake line works great. Just have to run an extension cord to the vacuum to stop blowing breakers.

Tim Baker

So I decided that since this was such a messy endeavor and there is probably a lot of interest I decided to design an adapter for the intake ports to aid in walnut shell blasting so far I've only made the covers, but it will give you the idea. There will be a sealed plate that bolts to the cylinder head that the vacuum and walnut shell blaster attach to. Additionally it covers the fuel injector ports to prevent the shells from going in the cylinder that way. If there is interest in this tool from others I can manufacture a more professional version. Here's the initial pics.

Intake port and fuel injector covers Made from 3/8 inch lexan designed to aid in walnutshell blasting. They bolt onto the head and slide over the lower intake manifold locating bolts.

Made from 3/8 inch lexan