TheBogie

Hi all,

Like many, I have battled the cold start lifter rattle with my 2011 3.8 for the last three winters at 39000 miles. I've spent hours reading all the posts about oil weight, filter ADBVs, using a block heater etc, here, BITGOG and other places. I have tried 5w-20 PYB dino, 5-30 Petro-Canada syn, 5w-20 & 5w30 Pennzoil Platinum with various filters including Mopar, Napa/Wix Gold, Napa/WIx Platinum, Fram Ultra Synthetic, and now Motorcraft FL400s. I have upgraded my wires and plugs, cleaned the throttle body, and seafoamed the CC every 2nd oil change.

At this point, I am getting my best results with Pennzoil 5w30 Platinum and Motorcraft FL400s by purolator. Admittedly, in "northern" Canada, my filter choices are limited... my stores almost always have FRAM only. I tried the FRAM Ultra due to its favorable reviews on BITGOG and its abundance. It was second best for rattling. The Motorcraft/PZ 5w30 combo nets me a mostly quiet cold start, the quietest operating valve train and smooth idling. I monitor oil pressure and temp with Autometer gauges, independently monitoring from a Mishimoto sandwich plate adapter with a braided line offset for accurate pressure. Pressures and temps, measured with my Autometer gauges, fall within good ranges for both cold and warm at idle and under load: (warm 17-psi - 60psi). My temp warms to 190F-140F depending on load conditions as expected.

In mornings below 40F, I plug my block heater in. This eliminates any cold start noise. But when at work and the JK is sitting all day, I still get some rattle as the temp dips.

I think that this is the best that I can do with an otherwise well-running 3.8. But my experiments gave some curious results that I hope someone can help me with.

On some filters, with temps between 0F-40F or lower, there was a 1-5 minute lag before pressure moved from zero as measured from the sandwich plate. The stock sensor does not flash any warnings so there is some pressure.

I know that the gauge is operating because on the Motorcraft, with the same oil and weight, I get pressure readings immediately. I can only think that some filters perform differently in the cold... perhaps the bypass settings are involved.

Any ideas?

39000 miles
2011 2dr Sahara

SiliconTi

Hmmm. I run NAPA Gold filter with Amsoil 5w-30 full synthetic and my pressure comes up almost immediately even in cold temp (I have 45K on the 3.8L).

I would say that a minute is too long - I'd not use that filter anymore.

Mr.T

Try the filter for a 2008 Jeep Liberty 3.7L engine (it also fits many other engines). It's about 25% longer, but looks like it has 50% more media, which reduces pressure drop. Even though the bypass should open if the filter has too much pressure loss -- Less pressure drop is better for oil flow.

It worked for me, and all I did at the time was replace the standard filter with the larger (didn't change oil).

Wix or Amsoil synthetic media filters are my favorites, but probably any good quality filter will have similar effect.

TheBogie

I'm using the Motorcraft Fl-400s which is the size used for the 3.7 I believe. It is the quietest so far and gives me immediate pressure readings at startup. The Fram Ultra (stock size) had delayed pressure readings when cold. Unfortunately I didn't have my new gauges in for the Mopar of Napa Gold and Platinums, so I don't know how they would have read when cold but they all clacked away on more than one filter so it's not worth going back to them. So far, I should just stick with the Motorcraft, but I am curious if the larger Napa/Wix 1516 would. No point in trying when what I have now is working. The pressure cold readings are a weird phenomenon that I wouldn't have even known about until I installed the gauges in October.

Mr.T

Yep, the FL-400S is the over-size filter. We both have the same solution, other than filter brand.

Pretty sure I remember reading that that synthetic filter media was less restrictive, Wix part number for that filter is 51516XP.