Cam gears are overheating

[Sambo34]

Ok so I have a 1st gen with a 4g63 engine non turbo. I recently replaced my head with a new refurbished one from some chi company in Texas. After finishing the job my car runs great but the cam gears are getting extremly hot and are smoking. But the camshafts are not that hot. I don't know if they are rubbing on something or grinding off the paint from the new head of what. Looking for any suggestion

 

[Chicken Patty]

I don't think there is such thing as "cam gears overheating". Probably burning off some grease or something. Do you have the cam gear cover on?

 

[Kapok6]

You sure the cams aren't hitting the cover?

 

[Sambo34]

The cam gears are smoking and getting hotter than the camshafts and the head. The cover is not on righ now an I just reset the timing a few days ago. The cams are not hitting anything either

 

[Archer Fabrications]

The cam gears are smoking and getting hotter than the camshafts and the head. The cover is not on righ now an I just reset the timing a few days ago. The cams are not hitting anything either

pix please

 

[evo9mrtt]

I think it would literally be impossible for the cam gears to get hotter than the cams. If anything they could only match the temp. If they were getting that hot a timing belt would just destroy itself. Are you sure your cam seals just aren't bad and your just seeing smoke from some burning oil? You say the head is fairly new but that doesn't mean that they didn't use cheap parts

Also how can you tell if the cams are cooler? Do you actually take off your valve cover off everytime you get done driving it and check with a temp gun? Not being a prick. Just curious questions is all

 

[Sambo34]

I just put in new can seals. And I can't hold my finger on the gears without burning it to hell. I can take the oil cap off and touch the intake cam and it is not as hot as the gears. I can actually touch it for a few seconds.

 

[Calan]

Did you torque the cam caps down and check that the cams rotated freely before installing the rockers?

Are you sure you set the timing belt tension correctly?

You have something seriously hosed if the gears are truly that hot; it's probably just a matter of time until the t-belt snaps and you bend valves. Don't run the car until you verify the above and find the source of the problem.

 

[spyderdrifter]

The only way I see them being able to get hotter is some sort of extra friction. Anyone know if an over tightened timing belt could cause this?

 

[Sambo34]

I torqued the cam gears to the correct spec with a torque wrench. I don't know how the belt could be too tight when there is an automatic tensioner. Please explain

 

[Calan]

I torqued the cam gears to the correct spec with a torque wrench.

I'm not talking about the cam gear bolts; I'm talking about the cam caps.

Did you torque the cam caps down and check that the cams rotated freely before installing the rockers?

EDIT:

Or for that matter, are you sure you put the caps in the right places and oriented correctly?

I don't know how the timing belt could be too tight when there is an automatic tensioner. Please explain

How did you set the timing belt tension?

 

[kchaazz]

Do what Calan is asking. Did you install the cams/rockers/lifters, or did a shop do it?

The timing belt can be too tight if you preload the eccentric with too much torque before tightening the bolt. Check the gap between the hydraulic tensioner rod and idler arm to confirm.

Take off the valve cover and confirm the cam caps are all installed in the correct order, if they are not, you are in a bit of trouble. Do this one first and take a pic. The cam caps are labelled and numbered, machined to fit only on their corresponding journals on the head, and if even one of them isn't in the correct position, the cam on that side will not spin freely.

Understand that if there is a friction issue with the cams binding in their journals, the cam gears could easily become hotter than the cams because the gears are not being cooled by oil.

 

[Calan]

Understand that if there is a friction issue with the cams binding in their journals, the cam gears could easily become hotter than the cams because the gears are not being cooled by oil.

Exactly ^.

And if the gears are aluminum, they will sink heat faster than the steel cams.

Assuming you adjusted the belt tension properly, my bet is that the cams are binding in their bores, due to mis-matched caps or a bad line bore.

With any head work, new cams, etc... you should always install the cams, properly torque the caps, and check for free rotation before installing the rockers.

 

[spyderdrifter]

If there's too much of a gap on the tensioner, or the tensioner arm pulley is positioned wrong, you can have an over tightened t-belt. I'm agreeing with what Calan is saying, but if that is the case, your cams would be seeing a higher temp as well, and possibly being grinded if the wrong caps are in the wrong locations due to misalignment.

 

[Sambo34]

The new head came with new cams and caps and rockers and lifters I did not install them myself. So I wouldn't know. I guess after work I will have to take off the valve cover and take a look but when I received the new head everything looked to be properly installed

 

[Chicken Patty]

^^ Inspect it and go from there, you have all the advise you need to get this going so far. Keep us posted. I'm willing to bet there's something that wasn't installed properly.